Conjugated polymer exciplexes and applications thereof

ABSTRACT

The present invention is directed to an exciplex formed from a π-conjugated polymer and an electron donor or acceptor component. The present invention also relates to assemblies comprising said exciplex, their use in optoelectrical devices and method of enhancing optoelectrical properties of π-conjugated polymers by forming said exciplex.

The invention described herein was made with Government support underGrant NSF CHE 912-0001 awarded by the National Science Foundation. TheGovernment has certain rights in the invention.

The present application is a continuation-in-part of U.S. Ser. No.146,266, filed on Nov. 2, 1993, the contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to polymers having optical and electroniccharacteristics well-suited for electronic, optoelectronic and photonicapplications. In particular, the present invention relates to acomposition comprising a π-conjugated polymer; specifically, an exciplexformed from a π-conjugated polymer and another component which,depending upon the circumstances, serves as an electron donor oracceptor. The exciplex of the present invention exhibits enhancedluminescence and photogeneration of charge carriers and excellentquantum efficiency. The present invention is also directed to assembliesand related devices incorporating the exciplex.

2. Background of the Invention

Recent advances in electronics, optoelectronics and photonics havecreated a need for new materials possessing the requisite optical,electrical and mechanical properties demanded for these applications. Aparticular class of materials of interest are polymers, which aregenerally more tractable and easier to process than conventionalinorganic semiconductor materials, which characteristics make possiblethe creation of large and flexible light emitting diodes (LEDs) fordisplays.

One of the more promising polymer candidates for such uses are theπ-conjugated polymers; that is, polymers whose backbone contain singlebonds alternating with double bonds (which include those provided by wayof rings and aromaticity) or triple bonds. Electrically conductingpolymers, including π-conjugated polymers, are known also to form groundstate charge transfer (CT) complexes, as described, e.g., by J. E.Frommer and R. R. Chance in Encycl. of Polymer Sci. & Eng., pp. 462-507(1985) and Wellinghoss et al. in U.S. Pat. No. 4,452,725, which patentdiscloses iodine and bromine CT complexes of poly(3,6-carbazoles). Inthese ground state CT complexes, the π-conjugated polymer can act as anelectron donor or electron acceptor, and small molecules can act aselectron donors or electron acceptors to form CT complexes in the groundstate; examples of such include iodine, bromine, AsF₅ and AsF₃. Whileπ-conjugated polymers have been employed in light emitting diodes,photodetectors, solar cells and electrographic photoreceptors, theysuffer from having less-than-desirable quantum efficiencies and thusultimately less-than-desirable electroluminescence device quantumefficiencies, which shortcomings include their inability to efficientlyemit spectrally pure, i.e., bright, blue light.

Efforts to increase electroluminescence device quantum efficiency inthis regard have been directed to "device engineering" techniques.Endeavors of this sort have focused on, for example, the type of metalelectrode used, the thickness of the emitter, the use of chargetransport layers to, among other things, improve electron transfer fromthe electrode, and the use of random copolymers in the device, asdescribed, for example, by Bradley in Adv. Mater. (1992), 4, 756;Burroughes, et al., Nature (1990) 347, 539; Braun, et al., Appl. Phys.Lett. (1991), 58, 1982; Gustafsson, et al., Nature (1992), 357, 477;Burn, et al., Nature (1992), 356, 47; Brown, et al., Chem. Phys. Lett.(1992), 200, 46.

As to the difficulty in efficiently obtaining spectrally pure blue lightemission from π-conjugated polymers, the problem with the same isassociated with an unusually large apparent Stokes shift between theabsorption and emission spectra for π-conjugated polymers and with theinability to control or predict a value for the apparent Stokes shiftfrom molecular structure. Hence, although there are many conjugatedpolymers with a π-π* transition energy on the order of about 2.8 eV orhigher, which value would appear adequate for obtaining blueluminescence, the aforementioned inability to predict the Stokes shiftthrows off any prediction from the π-π* transition energy. The largeStokes shift in π-conjugated polymers is believed to originate fromenergy relaxation in the course of excitation energy migration amongrandomly distributed chromophores of different conjugation lengths.

Blue light emitting conjugated and non-conjugated polymers have beenreported, including polymers such as poly(p-phenylene), as reported byGreen, et al., Adv. Mater. (1982), 4, 36; poly(alkylfluorene) asreported by Ohmari, et al., Jpn. J. Appl. Phys. (1991), 30, L1941; apolycarbonate derivative, as reported by Hosokawa, et al., Appl. Phys.Lett. (1992), 61, 2503; and a copolymer of poly(p-phenylene vinylene) asreported by Yang, et al., Macromolecules (1993), 26, 1188. Thesepolymers, however, emit blue light with less-than-desirable efficiencyand/or less than desirable spectral purity.

While attempts have been made to improve efficiency, these have been, asbefore stated, directed to device engineering techniques, which areusually hampered by the fact that the π-conjugated polymers have apropensity to form excimers; that is, excited state complexes formedfrom identical molecules. These complexes are generally stable in theexcited state, but are substantially dissociative in the ground state.Excimers are known to emit energy, whereafter they return to adissociated ground state; however, excimer emission from π-conjugatedpolymers gives rise to weak and inefficient luminescence because, inpart, they tend to emit energy in the form of heat rather thanluminescence, upon decay. For π-conjugated polymers, studies ofexcimer-like emissions have been made of poly(pyridine-2,5-diyl) byYamamoto, et al., J. Chem Soc. Chem. Commun. (1990), 1306.

In addition to excimer emissions of π-conjugated polymers, studies ofphoto-induced electron transfer betweenpoly[2-methoxy,5-(2'-ethyl-hexyloxy)-p-phenylene vinylene (MEH-PPV) andC₆₀, have been reported, Scaricifti, et al., Science, 258, 1474 (27 Nov.1992), the result here being ionization, i.e., the generation of ionradicals from the separation of charges, which does not result in highlyefficient luminescence.

Thus the art recognizes a continuing need to improve quantum efficiencyof π-conjugated polymers in regard to luminescence and photogenerationof charge carriers, including the pressing need for efficient generationof spectrally pure blue light.

SUMMARY OF THE INVENTION

The present invention achieves enhanced luminescence and photogenerationof charge carriers and increased quantum efficiency without beingstrictly limited to device engineering techniques. The present inventionis directed to a composition comprising an exciplex of a π-conjugatedpolymer. An exciplex is an excited state complex formed from differentmolecules. The exciplex forms when one or both of the componentmolecules are in an excited state and is stable in the excited state.The exciplex is substantially dissociative in the ground state; that is,there is no corresponding ground state interaction or complex formation.

In the present invention the π-conjugated polymer is the first componentthat forms the exciplex, and an electron donor or acceptor component isthe second component that forms the exciplex. The second component isdifferent from the first component and is effective to form the exciplexwith the first component when at least one of the first component or thesecond component is in an excited state.

The present invention is also directed to assemblies and optoelectronicdevices incorporating the exciplex.

The present invention is further directed to a method to enhanceoptoelectric properties of π-conjugated polymers by forming an exciplexfrom the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a light emitting diodecomprising a bilayer exciplex-forming assembly of the present invention.

FIG. 2 is a schematic representation of a light emitting diodecomprising a dispersed exciplex-forming assembly of the presentinvention.

FIG. 3 is a schematic representation of a photoreceptor/photoconductivedevice for electrophotographic imaging comprising a bilayerexciplex-forming assembly of the present invention.

FIG. 4 is a graph depicting the optical absorption spectra of a thinfilm of tris(p-tolyl)amine dispersed in a matrix of polycarbonate,TTA/PC, Curve 3; a thin film of Poly(benzobisoxazole-p-phenylene), PBO,Curve 1; and a bilayer thin film of PBO/TTA, Curve 2.

FIG. 5 is a graph depicting the photoluminescence (PL) spectra of a PBOthin film excited at 380 nm, Curve 3; a TTA/PC thin film excited at 380nm, Curve 2; and a PBO/TTA bilayer thin film excited at 380 nm, Curve 2.

FIG. 6A is a schematic representation of an assembly of the presentinvention useful in photoreceptor/photoconductive devices such asemployed in electrophotographic imaging, the assembly comprising apoly(p-phenylene benzobisthiazole), PBZT/TTA bilayer thin film assemblyprepared atop a nickel-coated poly(ethyleneterephthalate), PET,substrate.

FIG. 6B is a graph depicting the surface potential (volts) as measuredagainst exposure (ergs/cm²) for the assembly shown in FIG. 6A.

FIG. 7 is a graph depicting the quantum efficiency for chargephotogeneration, Φ, as measured against the electric field applied tothe assembly shown in FIG. 6A.

FIGS. 8 to 13 are schematic representatives of light emitting diodes oftransverse geometry.

FIGS. 14 and 15 are schematic representations of light emitting diodesof longitudinal geometry.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an exciplex formed from aπ-conjugated polymer and an electron donor or acceptor component that iseffective to form an exciplex with the π-conjugated polymer. As used inthe present specification the word "polymer" intends homopolymers andcopolymers even though copolymers may be separately identified herein. Aπ-conjugated polymer, as contemplated by the present invention, is apolymer whose backbone is substantially comprised of polyanthrazolinesas known in the art or as described in commonly-assigned WO 94/04592,published Mar. 3, 1994, the contents of which are incorporated herein byreference; polypyridines, such as poly(2,5-pyridine); polyimines;poly(phenylene vinylenes) such as poly(p-phenylene vinylene);polythiophenes; and poly(thiophene vinylenes).

In a specific aspect of the present invention, the π-conjugated polymercomprises a repeating unit having the structure: ##STR1## wherein Y is##STR2## Ar is a monocyclic or polycyclic aromatic moiety having 6 to 18ring atoms in said moiety or a nitrogen-, oxygen- or sulfur-containingheterocyclic moiety having from 5 to 18 ring atoms in said moiety, anyone of which moieties may be unsubstituted or substituted with one ormore lower alkyl, lower alkoxy, aryl or alkaryl, aralkyl, aroxy, nitro,hydroxy or halogen groups;

X and X₁ are each independently NR, oxygen or sulfur and each R isindependently hydrogen or lower alkyl;

Ar₁, Ar₂, Ar₃ and Ar₄ are each independently a monocyclic or polycyclicaromatic moiety having 6 to 18 ring atoms in said moiety or a nitrogen-,oxygen- or sulfur-containing heterocyclic moiety having 5 to 18 ringatoms in said moiety, any of which moieties may be unsubstituted orsubstituted with one or more lower alkyl, lower alkoxy, aryl, alkaryl,aralkyl, aroxy, nitro, hydroxy or halogen-groups;

R₁, R₂, R₃ and R₄ are each independently vinylene or ethynylene;

X₂, X₅, X₆ and X₉ are each independently nitrogen or CR₅, and X₃, X₄, X₇and X₈ are each independently nitrogen or CR₅ when not forming a pointof attachment, with the proviso that at least one but no more than twoof X₂, X₃, X₄ and X₅ is nitrogen and at least one but no more than twoof X₅, X₆, X₇ and X₅ is nitrogen and each R₅ is independently hydrogen,nitro, halogen, lower alkyl, lower alkoxy, alkaryl, aralkyl, amonocyclic or polycyclic aromatic moiety having 6 to 18 ring atoms insaid moiety or a nitrogen-, oxygen- or sulfur-containing heterocyclicmoiety having 5 to 18 ring atoms in said moiety, any of which may beunsubstituted or substituted with one or more halogen, lower alkyl,lower alkoxy or aroxy groups;

a, b, c and d are each independently 0 or an integer from 1 to 12;

e, f, g and h are each independently 0 or an integer from 1 to 6; and

n is an integer from 2 to 2000.

The substituents related in the formulae above and as may be recitedelsewhere in this specification are described as follows unlessotherwise indicated.

A monocyclic or polycyclic aromatic moiety having 6 to 18 ring atoms insaid moiety intends radicals formed from an aromatic moiety having 6 to18 carbon atoms, for example, 6 to 12 carbon atoms and 6 to 10 carbonatoms, the number of free valencies forming the radical being indicatedby the formulae given above or as may be recited elsewhere in thisspecification. Preferably, the free valencies forming the aromaticmoiety are at ring atoms. Examples of monocyclic aromatic moietiesinclude phenyl and phenylene; an example of a polycyclic aromatic moietyincludes those having ring systems that are fused, preferablyortho-fused, such as naphthyl and naphthylene, or that are joined by oneor more single bonds, such as biphenyl and biphenylene.

A monocyclic or polycyclic aromatic compound having from 6 to 18 ringatoms intends aromatic compounds having no free valencies and includessingle ring aromatic compounds such as benzene, and polycyclic aromaticring systems which may be fused or joined by one or more single bonds,such as anthracene, phenanthrene, naphthalene.

A nitrogen-, oxygen- or sulfur-containing heterocyclic moiety havingfrom 5 to 18 ring atoms intends radicals formed from heterocyclic ringswhich include at least one nitrogen, oxygen or sulfur ring atom butwhich may also include one or several of such atoms. The number of freevalencies forming the radical is indicated by the formulae given aboveor as elsewhere recited in this specification. It is preferred that thefree valencies forming the heterocyclic moiety are at ring atoms, morepreferably, carbon ring atoms. The expression includes radicals ofsaturated and unsaturated heterocyclics insofar as the requisiteconjugation is maintained, as well as heteroaromatic rings, which in thepractice of the present invention are preferred. The moiety may beformed from a single heterocyclic ring or it may be polycyclic, thelatter being formed from fused ring systems, preferably ortho-fused, orfrom ring systems joined by one or more single bonds. Representativemoieties in this regard include thienylene, especially 2,5-thienylene,pyridylene, especially, 2,5-pyridylene.

A nitrogen-, oxygen- or sulfur-containing heterocycylic compound havingfrom 5 to 18 ring atoms intends compounds having no free valencies andincludes saturated and unsaturated heterocyclics as well asheteroaromatics which in the practice of the present invention arepreferred. The heterocyclic compound may be a single ring compound or apolycyclic compound which may be formed from fused ring systems or ringsystems; joined by one or more single bonds.

The lower alkyl groups each contain up to 6 carbon atoms which may be inthe normal or branched configuration, including, without limitation,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl,pentyl, hexyl and the like. The preferred alkyl groups contain 1 to 3carbon atoms of which methyl is most preferred.

The lower alkoxy groups each contain up to 6 carbon atoms which may bein the normal or branched configuration, including without limitation,methoxy, ethoxy, propoxy and the like. The preferred alkoxy groupscontain 1 to 3 carbon atoms of which methoxy is most preferred.

The aryl groups are aromatic rings containing 6 to 14 carbon atoms. Anaryl group may be a single ring or a combination of multiple rings whichmay be ortho-fused or joined by one or more single bonds. Examples ofaryl groups include phenyl, α-naphthyl, β-naphthyl and biphenyl.

The alkaryl groups each contain up to 16 carbon atoms, with each alkylgroup thereof containing up to 6 carbon atoms, which may be in thenormal or branched configuration, and with each aryl group thereofcontaining from 6 to 10 carbon atoms. Preferably each alkyl groupcontains 1 to 3 carbon atoms and each aryl group contains 6 carbonatoms.

The aralkyl groups each contain up to 16 carbon atoms with each arylgroup thereof containing from 6 to 10 carbon atoms and each alkyl groupthereof containing up to 6 carbon atoms which may be in the normal orbranched configuration. Preferably, each aryl group contains 6 carbonatoms and each alkyl group contains 1 to 3 carbon atoms.

The aroxy (or aryloxy) groups each contain from 6 to 10 carbon atoms,with each aryl group preferably containing 6 carbon atoms.

Halogen includes fluorine, chlorine, bromine, iodine and astatine.Fluorine is preferred.

As employed herein, the hydroxy, nitro and cyano groups are --OH, --NO₂and --CN, respectively.

Vinylene may be in the ##STR3## form; trans being preferred.

Ethynylene is --C≡C--.

n is preferably an integer from 10 to 600; more preferably from 20 to200.

In a first aspect of the present invention, Y has Formula I; and Ar is amonocyclic or polycyclic aromatic moiety having 6 to 12 ring atoms insaid moiety. In a first configuration of this first aspect, Ar is##STR4## X and X₁ are each sulfur, and Ar₁ and Ar₂, when present, areeach independently a monocyclic or polycyclic aromatic moiety having 6to 10 ring atoms in said moiety. In a first embodiment thereof, Ar₂ is##STR5## c is 2 and a, b and d are each zero; the resultant polymerbeing poly(p-biphenylenebenzobisthiazole) (PBBZT), the repeating unitthus having the structure: ##STR6##

In a second embodiment, Ar₂ is ##STR7## c is 1 and a, b and d are eachzero; the resultant polymer being poly(p-phenylenebenzobisthiazole)(PBZT), the repeating unit thus having the structure: ##STR8##

In a third embodiment, Ar₂ is ##STR9## R₁ and R₂ are each vinylene; b, cand d are each 1 and a is zero; the resultant polymer beingpoly(benzobisthiazole-1,4-phenylenebisvinylene) (PBTPV), the repeatingunit thus having the structure: ##STR10##

In a fourth embodiment, Ar₂ is ##STR11## c is 1 and a, b and d are eachzero; the resultant polymer being poly(1,4-naphthylbenzobisthiazole)(1,4-PNBT), the repeating unit thus having the structure: ##STR12##

In a fifth embodiment, Ar₂ is ##STR13## c is 1 and a, b and d ar eachzero; the resultant polymer being poly(1,6-naphthylbenzobisthiazole)(1,6-PNBT), the repeating unit has the structure: ##STR14##

In a sixth embodiment, R₂ is vinylene, d is 2 and a, b and c are eachzero; the resultant polymer being poly(benzobisthiazole divinylene)(PBTDV), the repeating unit thus having the structure: ##STR15##

In a seventh embodiment, R₂ is vinylene, d is 1 and a, b and c are zero;the resultant polymer being poly(benzobisthiazole vinylene) (PBTV), therepeating unit thus having the structure: ##STR16##

In a second configuration of the present invention wherein Y has FormulaI, Ar is ##STR17## X and X₁ are each NR; and Ar₁ and Ar₂, when present,are each independently a monocyclic or polycyclic aromatic moiety having6 to 10 ring atoms in said moiety. In a first embodiment thereof X andX₁ are each NH, and a, b, c and d are each zero; the resultant polymerbeing poly(benzobisimidazole) (PBI), the repeating unit thus having thestructure: ##STR18##

In a second embodiment, X and X₁ are each NH, Ar₂ ##STR19## c is 1 anda, b and d are each zero; the resultant polymer being poly(p-phenylenebenzobisimidazole) (PBZI), the repeating unit thus having the structure:##STR20##

In a third embodiment, X and X₁ are each NH, R₂ is vinylene, d is 2 anda, b and d are each zero; the resultant polymer beingpoly(benzobisimidazole divinylene) (PBIDV), the repeating unit thushaving the structure: ##STR21##

In a fourth embodiment, X and X₁ are each NH, R₂ is vinylene, d is 1 anda, b and d are each zero; the resultant polymer beingpoly(benzobisimidazole vinylene) (PBIV), the repeating unit thus havingthe structure: ##STR22##

In a fifth embodiment, X and X₁ are each NH, R₁ and R₂ are eachvinylene, Ar₂ is ##STR23## b, c and d are each 1 and a is zero; theresultant polymer being poly(benzobisimidazole-1,4-phenylenebisvinylene) (PBIPV), the repeating unit thus having the structure:##STR24##

In a third configuration of the present invention wherein Y has FormulaI, Ar is ##STR25## and X and X₁ are each independently NR. In a firstembodiment thereof X and X₁ are each NH; R₂ is vinylene, d is 2 and a, band c are each zero; the resultant polymer being poly(bisbenzoimidazoledivinylene) (PBBIPV) the repeating unit thus having the structure:##STR26##

In a second aspect of the present invention, Y has Formula II and Ar isa monocyclic or polycyclic aromatic moiety having 6 to 12 ring atoms insaid moiety. In a first configuration of this second aspect of thepresent invention, Ar is ##STR27## and X and X₁ are each oxygen. In afirst embodiment thereof, Ar₂ is ##STR28## c is 1 and a, b and d areeach zero; the resultant polymer being poly(p-phenylene benzobisoxazole)(PBO), the repeating unit thus having the structure: ##STR29##

In a third aspect of the present invention, Y has Formula III and Ar isa monocyclic or polycyclic aromatic moiety having 6 to 12 carbon atomsin said moiety. In a first configuration of this third aspect of thepresent invention, Ar₂ is ##STR30## and a, b, c and d are each zero. Ina first embodiment thereof, Ar, is ##STR31## a is 1, and b, c and d areeach zero.

In a fourth aspect of the present invention, Y has Formula IX, i.e., Yis Ar. In a first configuration of this fourth aspect of the presentinvention, Ar is a monocyclic aromatic moiety. In a first embodimentthereof Ar is ##STR32## and a, b, c and d are each zero; the resultantpolymer being poly(p-phenylene), the repeating unit thus having thestructure: ##STR33## In a second embodiment, Ar is ##STR34## R₂ isvinylene, d is 1 and a, b and c are each zero; the resultant polymerbeing poly(p-phenylene vinylene), the repeating unit thus having thestructure: ##STR35##

In a second configuration of this fourth aspect of the presentinvention, Ar is a nitrogen-containing heterocyclic moiety. In a firstembodiment thereof, Ar is ##STR36## and a, b, c and d are each zero; theresultant polymer being poly(2,5-pyridine), the repeating unit thushaving the structure: ##STR37##

In a third configuration of this fourth aspect of the present inventionAr is a sulfur-containing heterocyclic moiety. In a first embodimentthereof, Ar is ##STR38## and a, b, c and d are each zero; the resultantpolymer being poly(2,5-thiophene), the repeating unit thus having thestructure: ##STR39## In a second embodiment, Ar is ##STR40## R₂ isvinylene, d is 1, a, b and c are each zero; the resultant polymer beingpoly(thiophene vinylene), the repeating unit thus having the structure:##STR41##

In a fifth aspect of the present invention, Y has Formula VII. In afirst configuration of the fifth aspect of the present invention, X₂ andX₆ are each nitrogen, X₃ and X₇ are each points of attachment, X₄, X₅,X₈ and X₉ are each independently CR₅ and e, f, g and h are each zero.Preferably the R₅ associated with X₄ and the R₅ associated with X₈ areeach hydrogen, and the R₅ associated with X₅ and the R₅ associated withX₉ are each phenyl. In a first embodiment thereof, R₂ is vinylene, d is1 and a, b and c are each zero; the resultant polymer being PVPQ, therepeating unit thus having the structure: ##STR42##

In a second embodiment, R₂ is ethynylene, d is 1 and a, b and c are eachzero; the resultant polymer being PAPQ, the repeating unit thus havingthe structure: ##STR43##

In a third embodiment, Ar₁ and Ar₂ are each ##STR44## R₂ is ethynylene;a, c and d are each 1 and b is zero; the resultant polymer being PBAPQ,the repeating unit thus having the structure: ##STR45##

In a fourth embodiment, Ar₂ is ##STR46## c is 1 and a, b and d are eachzero; the resultant polymer being PTPQ, the repeating unit thus havingthe structure: ##STR47##

In a fifth embodiment, Ar₂ is ##STR48## c is is 2 and a, b and d areeach zero; the resultant polymer being PBTPQ, the repeating unit thushaving the structure: ##STR49##

In a sixth embodiment, Ar₂ is ##STR50## c is 3 and a, b and d are eachzero; the resultant polymer being PTTPQ, the repeating unit thus havingthe structure: ##STR51##

In a seventh embodiment Ar₁ and Ar₂ are each ##STR52## R₂ is vinylene,a,c and d are each 1 and b is zero; the resultant polymer being PBTVPQ,the repeating unit thus having the structure: ##STR53##

In an eighth embodiment, Ar₁ and Ar₂ are each ##STR54## R₂ isethynylene, a, c and d are each 1 and b is zero; the resultant polymerbeing PBTAPQ, the repeating unit thus having the structure: ##STR55##

In a ninth embodiment, Ar₂ is ##STR56## c is 1, and a, b and d are eachzero; the repeating unit thus having the structure: ##STR57##

In a tenth embodiment, Ar₂ is ##STR58## c is 2 and a, b and d are eachzero; the repeating unit thus having the structure: ##STR59##

In an eleventh embodiment, Ar₂ is ##STR60## c is 2 and a, b and d areeach zero; the resultant polymer being the repeating unit thus havingthe structure: ##STR61##

In a sixth aspect of the present invention, Y has Formula VI. In a firstconfiguration of the sixth aspect of the present invention, X₂ and X₉are each nitrogen, X₃ and X₈ are each points of attachment and X₄, X₅,X₆ and X₇ are each independently CR₅. Preferably, the R₅ associated withX₄ and the R₅ associated with X₇ are each hydrogen and the R₅ associatedwith X₅ and the R₅ associated with X₆ are each phenyl. In a firstembodiment thereof, R₂ is vinylene, d is 1 and a, b and c are each zero;the resultant polymer being PVDA, the repeating unit thus having thestructure: ##STR62##

In a second embodiment, R₂ is ethynylene, d is 1, a, b and c are eachzero; the resultant polymer being PADA, the repeating unit thus havingthe structure: ##STR63##

In a third embodiment, Ar₁ and Ar₂ are each ##STR64## R₂ is vinylene, a,c and d are each 1 and b is zero; the resultant polymer being PSDA, therepeating unit thus having the structure: ##STR65##

In a fourth embodiment, Ar₁ and Ar₂ are each ##STR66## R₂ is ethynylene,a, c and d are each 1 and b is zero; the resultant polymer being PBADA,the repeating unit thus having the structure: ##STR67##

In a fifth embodiment, Ar₂ is ##STR68## c is 1, a, b and d are eachzero; the resultant polymer being PTDA, the repeating unit having thestructure: ##STR69##

In a sixth embodiment, Ar₂ is ##STR70## c is 2 and a, b and d are eachzero; the resultant polymer being PBTDA, the repeating unit thus havingthe structure: ##STR71##

In a seventh embodiment, Ar₂ is ##STR72## c is 3 and a, b and d are eachzero; the resultant polymer being PTTDA, the repeating unit thus havingthe structure: ##STR73##

In a eighth embodiment, Ar₁ and Ar₂ are each ##STR74## R₂ is vinylene,a, c and d are each 1 and b is zero; the resultant polymer being PBTVDA,the repeating unit thus having the structure: ##STR75##

In a ninth embodiment, Ar₁ and Ar₂ are each ##STR76## R₂ is ethynylene,a, c and d are each 1 and b is zero; the resultant polymer being PBTADA,the repeating unit thus having the structure: ##STR77##

In a tenth embodiment, Ar₂ is ##STR78## c is 1 and a, b and d are eachzero; the resultant polymer being the repeating unit thus having thestructure: ##STR79##

In a seventh aspect of the present invention Y has Formula VII and X₂and X₆ are each nitrogen, X₃ and X₇ are each points of attachment, X₄,X₅, X₈ and X₉ are each independently CR₅, f is 1 and e, g and h are eachzero. Preferably, the R₅ associated with X₄ and the R₅ associated withX₈ are each hydrogen, and the R₅ associated with X₅ and the R₅associated with X₉ are each phenyl. In a first configuration of theseventh aspect of the present invention, Ar₂ is ##STR80## c is 2, R₃ isethynylene and a, b and d are each zero; the resultant polymer beingPBTPQA, the repeating unit thus having the structure: ##STR81##

In a first embodiment thereof the phenyls associated with X₅ and X₉ areeach halogen substituted; preferably, each halogen-substituted phenylhas the structure: ##STR82## the resultant polymer being PBTPQA-F, therepeating unit thus having the structure: ##STR83##

In another practice of this first embodiment, R₃ is vinylene; theresultant polymer being PBTPQV-F, the repeating unit thus having thestructure: ##STR84##

In a second embodiment, the phenyls associated with X₅ and X₉ are eachsubstituted with alkoxy of up to carbon atoms; preferably, eachalkoxy-substituted phenyl has the structure: ##STR85## the resultantpolymer being PBTPQA-OCH₃ the repeating unit thus having the structure:##STR86##

In another practice of this second embodiment, R₃ is vinylene; theresultant polymer being PBTPQV-OCH₃, the repeating unit thus having thestructure: ##STR87##

In a third embodiment, Ar₂ is ##STR88## R₃ is vinylene, c is 1 and a, band d are each zero; the resultant polymer being PTPQV, the repeatingunit thus having the structure: ##STR89##

In a fourth embodiment, Ar₂ is ##STR90## R₃ is vinylene, c is 2 and a, band d are each zero; the resultant polymer being PBTPQV, the repeatingunit thus having the structure: ##STR91##

In a fifth embodiment Ar₂ is ##STR92## R₃ is vinylene, c is 3 and a, band d are each zero; the resultant polymer being PTTPQV, the repeatingunit thus having the structure: ##STR93##

In a sixth embodiment, Ar₁ and Ar₂ are each ##STR94## R₂ is ethynylene,R₃ is vinylene, a, c and d are each 1 and b is zero; the resultantpolymer being PBTAPQV, the repeating unit thus having the structure:##STR95##

In a seventh embodiment, Ar₁ and Ar₂ are each ##STR96## R₂ and R₃ areeach vinylene, a, c and d are each 1 and b is zero; the resultantpolymer being PBTVPQV, the repeating unit thus having the structure:##STR97##

In an eighth embodiment, Ar₂ is ##STR98## R₃ is vinylene, c is 2 and a,b and d are each zero; the resultant polymer being the repeating unitthus having the structure: ##STR99##

In an eighth aspect of the present invention, Y has Formula II and Ar is##STR100## Ar₂ is ##STR101## c is 1; and a, b and d are each zero.

In a ninth aspect of the present invention, the π-conjugated polymercomprises a repeating unit having the structure: ##STR102##

In Formulae X and XI, which are generally directed to polyimines, R₆ andR₈ are each independently vinylene, ethynylene, a monocyclic orpolycyclic aromatic moiety having 6 to 18 ring atoms in said moiety or anitrogen-, oxygen- or sulfur-containing heterocyclic moiety having 5 to18 ring atoms in said moiety, any of which moieties may be unsubstitutedor substituted with one or more lower alkyl, lower alkoxy, aryl,alkaryl, aralkyl, aroxy, halogen, nitro or hydroxy groups. Also inFormulae X and XI, R₇ and R₉ are each independently hydrogen, loweralkyl, alkaryl, aralkyl or aryl; i and j are each independently 0 or aninteger from 1 to 12 and n is an integer from 2 to 2000.

In a first configuration of this ninth aspect of the present invention,the π-conjugated polymer has Formula XI and R₇ and R₉ are each hydrogen.In a first embodiment thereof, R₆ and R₈ are each ##STR103## and i and jare each 1; the repeating unit thus having the structure: ##STR104##

In a tenth aspect of the present invention, the π-conjugated polymercomprises a repeating unit having the structure: ##STR105## wherein Ar₅is ##STR106## and Ar₆ is ##STR107## wherein Ar₇ is ##STR108## whereinAr₈ is ##STR109## Ar₅ has the meaning given above, X₁₀ and X₁₁ are eachindependently sulfur, oxygen or NR₅ wherein R₅ is hydrogen, lower alkyl,alkoxy or an aryl group; ##STR110## wherein Ar₉ is ##STR111## and X₁₀has the meaning given above; ##STR112## wherein Ar₅, X₁₀ and X₁₁ havethe meanings given above and n is an integer from 2 to 2000.

The π-conjugated polymers contemplated by the present invention are notlimited to homopolymers having the repeating structural units recitedhereinabove. Copolymers of at least two repeating structural unitswithin the scope of one or more of the above generic repeatingstructural units are within the practice of the present invention.

More particularly in this regard, a π-conjugated polymer contemplated bythe present invention may be a random or block copolymer whichpreferably comprises only two of the repeating structural units ashereinbefore defined. Generally, the mole ratio of a first repeatingunit to a second, different repeating unit is anywhere from about 0.5:95to about 95:0.5. Other mole fractions preferred in this regard are about90:10 to about 10:90; about 80:20 to about 20:80; about 70:30 to about30:70; about 60:40 to about 40:60; and about 50:50.

Examples of preferred copolymers in this regard include PBPQ/PBAPQ shownbelow: ##STR113##

PBAPQ/PSPQ shown below: ##STR114##

PBTPQA-F/PTBPQ shown below: ##STR115##

PBTPQA-OCH₃ /PBTPQ shown below: ##STR116##

PBPQ/PSPQ shown below: ##STR117##

Also among the copolymers contemplated by the present invention is onehaving the repeating structural unit: ##STR118## where w is O or aninteger from 1 to 18, k and l are each independently an integer of 2 to2000, h is an integer from 1 to 10, and each X₁₃ is independentlysulfur, oxygen or NR₁₅ where R₁₅ is hydrogen or lower alkyl.

The preparation and properties of the π-conjugated polymers aregenerally known in the art or are described in commonly-assignedWO94/04592, published Mar. 3, 1994, the contents of which areincorporated herein by reference.

Thus, for example, a π-conjugated polymer which broadly falls within thescope of Formula I where Ar is ##STR119## can generally be prepared bydissolving a compound having the structural formula: ##STR120## whereX₁₂ is sulfur oxygen or NR₁₄ and R₁₄ is hydrogen or lower alkyl. In thisformula, p is 2 when X₁₂ is sulfur or oxygen and p is 4 when X₁₂ isNR₁₄, preferably in polyphosphoric acid (PPA). Compounds meeting thisformula include, e.g., 1,2,4,5-tetraaminobenzenetetrahydrochloride,1,4-diamino-2,5-dithiobenzenedihydrochloride and1,4-diamino-2,5-diolbenzenedihydrochloride. Preferably, these compoundsare dehydrochlorinated by first being dissolved in 70% to 80% deaeratedPPA. More preferably, 77% PPA is employed, as formed from 100% PPA and85% phosphoric acid, which dissolves1,2,4,5-tetraaminobenzenetetrahydrochloride or1,4-diamino-2,5-dithiobenzenedihydrochloride. The solution is adihydrochlorinated product and is then contacted with a compound havingthe structural formula:

    COOH--R.sub.15 --COOH or

    COOH--R.sub.15 --R.sub.15 --COOH

where each R₁₅ is the same or different and is alkyl, aryl, aralkylalkaryl. To compensate for the water of condensation lost in heating,additional phosphorous pentoxide (P₂ O₅) is added. Compounds meetingthis formula include, e.g., fumaric acid, oxidic acid and trans,transmuconic acid. The product is heated for an extended period of timeand thereafter cooled. The polymeric product is obtained byprecipitation in water and purified by extracting the PPA with water.

Another example, the preparation of π-conjugated polymers broadlyfalling within the scope of Formula V, especially where Ar is ##STR121##and e, f and h are each zero can be accomplished generallydehydrochlorinating a compound having the structural formula: ##STR122##where X₁₂ has the meaning given above, in the presence of PPA followedby reacting the dehydrochlorinated product with trans, trans muconicacid. A compound meeting this formula includes 3,3'-diamino benzidine.It is preferred that the PPA utilized in this synthesis is between 80and 90% weight % PPA.

As contemplated by the present invention, the π-conjugated polymer firstcomponent can act as either an electron donor or an electron acceptor,depending primarily upon the character of the second component andwhether it is a stronger electron donor or electron acceptor than theπ-conjugated polymer first component.

As appreciated by those of skill in the art, an electron acceptor ischaracterized by the relative ease it can accept electrons, whichproperty is generally established by the measurement known in the art asreduction potential or electron affinity. An electron donor on the otherhand is characterized by the relative ease it can give up electrons,which property is generally established by the measurement known in theart as oxidation potential or ionization potential. Both oxidationpotential and reduction potential are related to ionization potentialand electron affinity, respectively.

For purposes of the present invention, reduction potential and oxidationpotential can be measured by conventionally known techniques. Apreferred technique in this regard is cyclic voltammetry.

In the practice of the present invention, once a particular π-conjugatedpolymer is chosen as the first component, a determination can be made asto its reduction potential and its oxidation potential. A suitableelectron donor as a second component is that which has an oxidationpotential less than that of the π-conjugated polymer. A suitableelectron acceptor is that which has a reduction potential greater thanthat of the π-conjugated polymer.

In the practice of the present invention, the electron donor or acceptorsecond component is generally a small molecule or polymer, including aπ-conjugated polymer as hereinbefore defined with the proviso that it bedifferent from the π-conjugated polymer selected as the first component.A small molecule or polymer in this regard includes, without limitation,a monocyclic or polycyclic aromatic compound having from 6 to 18 ringatoms, a nitrogen-, oxygen- or sulfur-containing heterocyclic compoundhaving from 5 to 18 ring atoms, any of which compounds may beunsubstituted or substituted with one or more lower alkyl, lower alkoxy,aryl, aralkyl, alkaryl, aroxy, cyano, nitro, hydroxy or halogen groups.Examples of suitable compounds in this regard include anthracene,9,10-dicyanoanthracene, tetracyanobenzene or 9,10-dimethylanthracene.

Other small molecules suitable in this regard includesnitrogen-containing compounds having the structure: ##STR123## whereinR₁₀, R₁₁, R₁₂ and R₁₃ are each independently hydrogen, lower alkyl,aryl, aralkyl, alkaryl, wherein the aryl, aralkyl or alkaryl groups maybe substituted with one or more lower alkyl groups; Ar₁₁ is a monocyclicor polycyclic aromatic moiety having 6 to 18 ring atoms in said moietywhich moiety may be unsubstituted or substituted with one or more loweralkyl groups with the proviso that in Formula XII not more than two ofR₁₀, R₁₁ and R₁₂ are hydrogen. Preferably in regard to Formula XII, R₁₀and R₁₁ are each alkyl and R₁₂ is aryl. Examples of suitable Formula XIInitrogen-containing compounds in this regard includeN,N'-dimethylaniline, N,N'-diethylaniline,N,N'-diphenyl-N-N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine,tri(p-dimethylamino-phenyl)amine or tris(p-tolyl)amine.Tris(p-tolyl)amine is particularly preferred in this regard.

In regard to Formula XIII it is preferred if R₁₀, R₁₁, R₁₂ and R₁₃ areeach lower alkyl, more preferably ethyl or methyl. Examples of preferredembodiments in this regard includeN,N,N',N'-tetramethyl-1,4-phenyldiamine where Ar₁₁ is p-phenylene andR₁₀, R₁₁, R₁₂ and R₁₃ are each methyl;N,N,N',N'-tetraphenyl-1,4-phenylenediamine where Ar₁₁ is p-phenylene andR₁₀, R₁₁, R₁₂ and R₁₃ are each ethyl;N,N,N',N'-tetraphenyl-1,4-phenylenediamine where Ar₁₁ is p-phenylene andR₁₀, R₁₁, R₁₂ and R₁₃ are each phenyl; andN,N,N',N'-tetratolyl-1,4-phenylene diamine where Ar₁₁ is p-phenylene andR₁₀, R₁₁, R₁₂ and R₁₃ are each tolyl, preferably m-tolyl. Other examplesof preferred embodiments in this regard includeN,N'-ditolyl-(N,N'-diphenyl)4,4'-diamine where Ar₁₁ is 1,1'-biphenyl andR₁₀ and R₁₃ are each phenyl and R₁₁ and R₁₂ are each tolyl, preferablym-tolyl (TPD); N,N,N',N'-tetraphenyl-(1,1'-biphenyl)-4,4'-diamine whereAr₁₁ is 1,1'-biphenyl and R₁₀, R₁₁, R₁₂ and R₁₃ are each methyl; andN,N,N',N'-tetraethyl-(1,1'-biphenyl)-4,4'-diamine where Ar₁₁ is1,1'-biphenyl and R₁₀, R₁₁, R₁₂ and R₁₃ are each ethyl.

A small molecule or polymer also contemplated by the present inventionincludes a polymer that has as part of its repeating unit a moiety ofthe above-defined monocyclic or polycyclic aromatic compounds ornitrogen-, oxygen- or sulfur-containing heterocyclic compounds useful asthe electron donor or acceptor component. In this regard, the moiety mayappear in the backbone of said polymer or as a side chain or as asubstituent attached to said backbone. An example of a polymer in thisregard includes polyvinylcarbazole having a repeating unit of thegeneral formula: ##STR124## wherein the carbazole moiety falls withinthe scope of nitrogen-containing heterocyclic compounds contemplated bythe present invention as an electron donor or acceptor component, thecarbazole moiety appearing as a side group to the backbone of thepolymer.

In another aspect, the present invention relates to an assemblycomprising the π-conjugated polymer and the electron donor or acceptorcomponent, the π-conjugated polymer and the electron donor or acceptorcomponent having a physical contact relationship in said assembly thatis sufficient to permit the exciplex to form when at least one of theπ-conjugated polymer or the electron donor or acceptor component is inan excited state.

The assembly can be a bilayer or multilayer structure. Preferably thelayers are comprised of thin films of the π-conjugated polymer and theelectron donor or acceptor component. Preferably, the films are lessthan 1000 nm thick; more preferably less than 500 nm thick; still morepreferably less than 100 nm thick. In the most preferred practice,optimal exciplex optical and electrical properties are obtained when thethickness of the films is less than or equal to the absorption thicknessof the material, the values for which are obtainable from the absorptioncoefficient of the material as can be conventionally measured. In oneembodiment of the bilayer or multilayer assembly, the π-conjugatedpolymer is contained in a first layer and the electron donor or acceptorcomponent is contained in a second layer, the first layer being adheredto the second layer sufficient to permit the exciplex to form when atleast one of the first or the second layers is excited. As contemplatedherein, adhered intends a contact relationship between the first and thesecond layers be it by chemical, mechanical or electrical forces ormeans which contact relationship is adequate for the exciplex to form.For a multilayer assembly, the first layer, containing a π-conjugatedpolymer, and the second layer, containing a suitable electron donor oracceptor component, alternate to form a plurality of such layers. In thepractice of this aspect of the present invention each "first" layer maycontain the same or different π-conjugated polymer and each "second"layer may contain the same or different electron donor or acceptorcompounds. Preferably, each "first" layer contains the same π-conjugatedpolymer and each "second" layer contains the same electron donor oracceptor component.

In a preferred embodiment of the layered assembly, the first or secondlayer is adhered to a substrate, such as glass, fused silica or an inertpolymer, including e.g., polycarbonate, polymethylmethacrylate,poly(ethylene terephthalate) or polystyrene.

In practice, the first and second layers may be formed and adhered asconventionally known in the art. Preferably, the π-conjugated polymer issolubilized using an aprotic solvent, such as a nitroalkane, and a Lewisacid, such as aluminum chloride, as described, for example, in Jenekhe,et al., Macromolecules (1989), 22, 3216; Jenekhe, et al., Macromolecules(1990), 23, 4419; and commonly-assigned U.S. Ser. No. 934,610, filedAug. 24, 1992, the contents of which are incorporated herein byreference.

The resulting solution may be applied to a substrate by conventionalmeans, e.g., by spin coating, and the coating may be washed with a Lewisbase, such as deionized water, to decomplex the π-conjugated polymerfrom the Lewis acid.

The films may be dried to remove the water, after which a solutioncontaining the electron donor or acceptor may be applied atop of theπ-conjugated polymer coat. The electron donor or acceptor component maybe dispersed, for example, in a polycarbonate or like material, andplaced into solution with a halogen-containing alkane. It will beappreciated that the order of film formation may be reversed; that is,the electron donor or acceptor-containing coating may be applied to thesubstrate first, with the π-conjugated polymer coating applied atop ofit.

The π-conjugated polymer or electron donor or acceptor may be excited bytechniques known in the art. Thus the excited state may be (1)photogenerated by absorption of light, e.g., photoexcitation by laser;(2) electrically generated, by injection of negative and positivecharges, e.g., by injecting negative and positive charges into theassembly containing the π-conjugated polymer and the electron donor oracceptor component through electrodes; (3) by electrochemicallygenerating charged ions in the π-conjugated polymer or electron donor oracceptor component; and (4) chemically generating radical ions in theπ-conjugated polymer or electron donor or acceptor component.

In another embodiment, the assembly may be a dispersed assembly whereinthe π-conjugated polymer is molecularly dispersed in the electron donoror acceptor or a matrix containing the same; or the electron donor oracceptor is molecularly dispersed in the π-conjugated polymer or amatrix containing the same; or both the π-conjugated polymer and theelectron donor or acceptor are molecularly dispersed in an inert matrix,such as an inert polymer matrix, e.g., polycarbonate, polymethylmethacrylate, polyethylene terephthalate, polystyrene and like polymers.

The assembly of the present invention, be it layered, dispersed orotherwise, may be part of article of manufacture. Thus, an article ofmanufacture, such as a light emitting diode, a xerographicphotoreceptor, a solar cell, a photodetector, a laser, a waveguide, aswitch or a modulator may be comprised of the assembly of the inventionand may further comprise means for generating the excited state.Articles such as the devices elaborated above, comprising the assemblyof the present invention may be fabricated according to techniques knownin the art.

Of especial interest of the optoelectrical devices incorporating anassembly of the present invention are electroluminescent light emittingdiodes (LEDs) and photoconductive devices for electrophotographicimaging.

An example of an electroluminescent device for light emission employingthe exciplex and assembly of the present invention is shown in FIG. 1.As illustrated in FIG. 1, layer 1 is a transparent substrate such asglass or plastic such as PET; layer 2 is a transparent conductiveelectrode, such as indiumtinoxide (ITO), or a thin film of gold or aconductive polymer such as polyaniline. Layer 3 is comprised of theπ-conjugated polymer as hereinbefore defined. Layer 4 is comprised ofthe electron donor or acceptor second component as hereinbefore defined;typically, the second component acts as an electron donor and theπ-conjugated polymer as an electron acceptor. Layer 5 is a conductiveelectrode comprised of, e.g., aluminum (Al), magnesium (Mg), calcium(Ca) or combinations thereof. The thickness of layers 1, 2 and 5 are notcritical to device performance and may hence be of conventionaldimensions. The thickness of either layer 3 or 4, preferably both 3 and4, are between about 10 to about 1000 nm. By applying a sufficientvoltage, V, in the LED of FIG. 1, light is emitted, the emission colorfrom the exciplex depending upon the choice of π-conjugated polymer andelectron donor or acceptor component.

It is theorized that electrical excitation of the assembly of thepresent invention, represented by layers 3 and 4 in FIG. 1, byapplication of voltage leads to the formation of the same exciplex aswhen excitation is by absorption of light (photoexcitation). Electricalexcitation as in FIG. 1, leads to the injection of electrons from layer5 into layer 4 and the injection of holes from layer 2 to layer 3 whichcircumstances result in the charged species (represented in FIG. 1 asthe π-conjugated polymer acting as an electron acceptor). These speciesrecombine to give the exciplex, the radiative decay of which results inthe light emitted by the device. As discussed herein spectral tunabilityof emission can be obtained by fixing the choice of π-conjugated polymer(here acting as an electron acceptor, A) and varying the electron donoror acceptor component (here, an electron donor, D) or by fixing thelatter and varying the former.

Another example of an electroluminescent device employing the exciplexand assembly of the present invention is shown in FIG. 2. As illustratedin FIG. 2, layers 1 and 2 are as defined in FIG. 1 and layer 4 is aconductive electrode comprised of, e.g., aluminum, magnesium, calcium orcombinations thereof. Layer 3 constitutes a dispersed assembly of theπ-conjugated polymer as hereinbefore defined and an electron donor oracceptor component as hereinbefore defined. In FIG. 2, layer 3 may be adispersion of the π-conjugated polymer in the electron donor or acceptorcomponent; or a dispersion of the electron donor or acceptor componentin the π-conjugated polymer; or a dispersion of the π-conjugated polymerand the electron donor or acceptor component in an inert matrix such aspolycarbonate, polymethylmethacrylate, polystyrene or like compounds.The preferred thickness of layer 3 of FIG. 2 is between about 10 toabout 1000 nm.

An example of a bilayer photoreceptor or photoconductive device forelectrophotographic imaging employing the exciplex and assembly of thepresent invention is shown in FIG. 3. As illustrated in FIG. 3, layer 1is a substrate which is a plastic film coated with a metal conductor,e.g., PET coated with nickel (Ni). Layers 2 and 3 constitute the activephotoreceptor material system from which the exciplex forms. Layer 2 isa π-conjugated polymer as hereinbefore defined and Layer 3 is anelectron donor or acceptor component as hereinbefore defined.Xerographic imaging with the bilayer photoreceptor of FIG. 3 involves,first, application of a surface charge on top of layer 3 by coronacharging. Subsequently, photoexcitation of layer 2, here acting as anelectron acceptor, A, leads to the formation of the exciplex of thepresent invention:

    D+A*→(DA*)→(D.sup.+. A.sup.-.)*

The presence of electric field assists in the dissociation of theexciplex into charge carriers:

    (D.sup.+. A.sup.-.)*→D.sup.+. +A.sup.-..

By changing the composition of the exciplex, i.e., by varying theπ-conjugated polymer and/or the electron donor or acceptor component,the charge photogeneration efficiency as well as the wavelength rangeover which the device is responsive can be varied and controlled.

In another embodiment, the exciplexes of the present invention may beused in or as a self-protecting composite for structures; that is, asstabilizing materials against photodegradation. For example, theπ-conjugated polymer and electron donor or acceptor material, in layeredor dispersed assembly, may be applied as a coating to structures thatare subject or prone to photodegradation. When these structures areexposed to light, an exciplex will form from the π-conjugated polymerand the electron donor or acceptor compound. The energy that wouldotherwise photodegrade the structure is instead employed for exciplexformation.

In another aspect, the present invention relates to a method ofenhancing the opto-electric properties of a π-conjugated polymer. Themethod comprises forming an exciplex of the π-conjugated polymer and anelectron donor or acceptor component, the exciplex having, e.g.,enhanced luminescence over the pure polymer and enhanced photogenerationof charge carriers.

In another embodiment, the luminescence of exciplexes formed inaccordance with the invention may be color tuned by selecting anappropriate electron donor or acceptor component for a particularπ-conjugated polymer or by selecting an appropriate π-conjugated polymerfor a particular electron donor or acceptor component. For example, thepeak luminescence (λ_(max)) for exciplexes formed from a particularelectron donor or acceptor component with differing π-conjugatedpolymers has a linear relationship with the reduction potential (V vs.SCE) for each of the π-conjugated polymers. Thus one can predict withreasonable certainty which polymer to employ to obtain a given color byknowing the reduction and/or oxidation potential of that polymer. Thesame is true if a particular π-conjugated polymer is used and one variesthe electron donor or acceptor component, with accompanying measurementof peak luminescence (λ_(max)) and reduction and/or oxidation potentialfor the electron donor or acceptor components.

The π-conjugated polymers identified herein may themselves be useful ina process to produce light wherein a source of energy is imposed upon apolymeric film. The polymeric film may be a film of a homopolymer of anyof the polymers having a repeating structural unit within thecontemplation of any of formulae given above. Moreover, the polymericfilm may be a film of a copolymer having a repeating structural unitencompassing two or more repeating structural units of one or more offormulae given above.

The process of producing light by imposing a source of energy upon apolymeric film is moreover preferably characterized by the source ofenergy provided by a voltage source.

The π-conjugated polymers identified hereinabove may themselves beemployed to fabricate a light emitting diode. The light emitting diodeincludes a polymeric film formed from a homopolymer or a copolymercharacterized by one or more, respectively, repeating structural unitswithin the scope of one or more repeating structural units of theformulae given above. The polymeric film of the light emitting diode isin electrical communication with positive and negative electrodes (anodeand cathode respectively) which, in turn, are in electric communicationwith a voltage source.

Although all of the above described elements are required of the lightemitting diode of the present invention, additional components andfeatures may be provided. For example, the film may be disposed upon asubstrate which may or not be ion-implanted. Furthermore, a portion ofthe polymeric film may be ion implanted to provide a positive and/ornegative charge therein. These features will become readilyunderstandable upon an analysis of specific embodiments of lightemitting diodes discussed herein.

Prior to this discussion it is important to emphasize that lightemitting diodes here include an LED of transverse geometry and an LED oflongitudinal geometry. A polymeric LED of transverse geometry providesvertical surface light emission. A polymeric LED of longitudinalgeometry provides edge light emission.

With this introduction, attention is focused initially upon LEDs oftransverse geometry. Six embodiments of LEDs of transverse geometry arepreferred for use in the present invention.

Turning to the first such design, illustrated in FIG. 8, that diodeincludes a polymeric film of a polymer within the contemplation of thelight emitting device of the present invention having at least onerepeating structural unit within the contemplation of formulae givenabove. That film, denoted by reference numeral 2, is disposed upon asubstrate 3. A layer of substrate 3, in contact with the film 2, isionically implanted to provide a positive electrode, that is, an anodeidentified at 7. In these light emitting diodes, a second, negativelycharged electrode, the cathode, denoted at 5, is also included. Thecathode 5, like the anode 7, is in electrical communication with thepolymeric film 2. The cathode 5 in the LED of FIG. 8 is a metalelectrode. Both electrodes 5 and 7 are in electrical communication,through electrical conduit 9, to a voltage source 11. Upon imposition ofa electrical charge, the polymeric film emits light through a verticalsurface, in this case light emission occurs through the substrate, sideas indicated in FIG. 8 by the arrow 1.

It is emphasized that the light emitting device of this invention mayinclude more than one polymeric film layers. The light emitting diode ofFIG. 9 is identical to the LED of FIG. 8 but for the inclusion of alaminate of two polymeric films, denoted by film layers 4 and 6, ratherthan the single layer polymeric film 2 of the light emitting device ofFIG. 8.

It is noted that the light emitting devices of FIGS. 8 and 9 employ acathode 5 which covers the complete surface of the polymeric film. Amore modestly sized electrode, which does not cover the full surface ofthe polymeric film, can also be utilized. In this preferred LEDembodiment, however, the surface of the film in contact with theelectrode is ion-implanted to provide a positive or negative charge.Such an LED is provided in FIG. 10.

The light emitting diode of FIG. 10 is similar to the light emittingdiode of FIG. 8. Thus, the anode is again provided by the same p-typedoped portion 7 of the same substrate 3 as FIG. 8. The anode 7 is inelectrical communication with a similar voltage source 11 by means ofsimilar electrical conduit 9. However, the polymeric film of the LED ofFIG. 10, identified by 8, includes an n-type ion implant layer 12 inelectrical communication with a metal cathode 10. The cathode 10 is inelectrical communication, again by means of electrical conduit 9, to avoltage source 11. The polymeric film 8 also includes a non-ionimplanted layer 13. The LED of FIG. 10 also emits light through avertical surface, again, as in the LEDs of FIGS. 8 and 9, through thesubstrate. This is depicted in FIG. 10 by the light designating arrow 1.

Another embodiment of a light emitting device is depicted in FIG. 11.The light emitting diode of FIG. 11, like the light emitting diodes ofFIGS. 8 to 10, is again a vertical surface light emitting diode oftransverse geometry. The light emitting diode of FIG. 11 is similar tothe light emitting diode of FIG. 10. However, although the polymericfilm of the light emitting diode of FIG. 4 is similar to that of FIG. 3,in that they both include a polymeric film 4 which comprises a n-typeion implant layer 12 as well as an undoped layer 13, there arevariations in the substrate and the metal electrode elements thereof.

Whereas the substrate 3 of the LED of FIG. 10 includes an electrodelayer 7, the substrate of the LED of FIG. 11, denoted at 15, includes ap-type ion implant layer 17. This layer is not an anode in the sensethat is electrode 7 of substrate 3. Instead, a metal anode 16 isprovided in electrical communication with the p-type ion implant layer17 of substrate 15.

A further embodiment of a light emitting diode is illustrated FIG. 12.The LED of FIG. 12 includes a polymeric film 20 which is doped with ap-type ion implant 22 and an n-type ion implant 24. These ion implantportions of polymeric film 20 are disposed immediately below a metalanode 26 and a metal cathode 28, respectively. These electrodes are inelectrical communication, by means of an electrical conduit 9, to avoltage source 11. The polymeric film 20 is disposed on a implant freesubstrate 18. Light is emitted through the polymeric film as denoted bylight arrow 1.

Yet a sixth embodiment of an LED of transverse geometry is depicted inFIG. 13. The LED of FIG. 13 includes a free-standing polymeric film 30which includes an n-type ion implant layer 32 and a p-type ion implantedlayer 33 sandwiching therebetween a non-doped film layer 31. A metalcathode 34 contacts the n-type ion implant layer 32 while a metal anode35 is in contact with the p-type ion implant layer 33 of the polymericfilm 30. As in the LEDs of FIGS. 8 to 12, the cathode 34 and the anode35 are in electrical communication, by means of electrical conduit 9,with a voltage source 11. Light is emitted vertically through thesubstrate-free polymer as indicated by arrow 1.

In addition to the light emitting diodes of transverse geometry,illustrated by FIGS. 8 to 13, additional light emitting diodes oflongitudinal geometry are employable. These diodes are again polymericLEDs. An LED of longitudinal geometry is distinguished from an LED oftransverse geometry insofar as an LED of transverse geometry providesvertical surface light emission in contradistinction to an LED oflongitudinal geometry which emits light through the edges of the film.

To illustrate an LED of longitudinal geometry, attention is directed toFIG. 14. The light emitting diode of FIG. 14 incorporates a polymericfilm of similar design to that utilized in the light emitting device ofFIG. 13. That is, the polymeric film, generally indicated at 30,includes an n-type ion implant layer 32 and a p-type ion implant layer33 on the surfaces sandwiching therebetween a non-ion implant layer 31.

It is appreciated that reference numerals for the polymeric film of theLED of FIG. 14 are identical with the polymeric film of the LED of FIG.13. This is because the two freestanding polymeric films of the LEDs ofFIGS. 13 and 14 are identical. What distinguishes the LED oflongitudinal geometry of FIG. 14 from the LED of transverse geometry ofFIG. 13 is the size and disposition of the electrodes. Although bothLEDs employ metal electrodes, the metal electrodes employed in the LEDof FIG. 14 completely cover polymeric film 30 such that there is nooptical transmission between that film and its surfaces. This isillustrated in the LED of FIG. 14 by the metal cathode 36, disposedabove the n-type implant layer 32, and the metal anode 37, disposedbelow the p-type ion implant layer 33. As in the embodiments of LEDs oftransverse geometry, the metal electrodes are in electricalcommunication with a voltage source 11 provided by means of electricalconduit 9. Because metal electrodes 36 and 37 block light transmission,light is emitted from the polymeric film 30 through its edges asindicated by the arrow 1. Obviously, the electrodes 34 and 35 of the LEDof transverse geometry of FIG. 6 is not obstruct vertical lightemission.

The final preferred embodiment depicted in the drawings is set forth inFIG. 15. FIG. 15 represents another preferred embodiment of an LED oflongitudinal geometry. As in the light emitting diode of FIG. 14, thelight emitting diode of FIG. 15 encompasses a polymeric film whoseprincipal surfaces are completely covered by metal electrodes. This isdepicted in the light emitting diode of FIG. 15 by metal cathode 38 andmetal anode 39. The device of FIG. 15 differs from the light emittingdevice of FIG. 14 in that the polymeric film 40 is undoped. That is, noion implant layers are provided. Thus, the polymeric film 40 iscompletely surrounded by electrodes 38 and 39 which block vertical lighttransmission. As in the light emitting diode of FIG. 14, light isemitted through the polymeric film edges as denoted by the arrow 1.

Several aspects of the afore-described LEDs merit emphasis. The first isthat a critical component of the light emitting diode of the presentinvention is the π-conjugated polymeric film. Although other componentsof the light emitting diode are important in optimizing itseffectiveness, it is the polymeric film which is the key component.Obviously, the light emitting diode also requires an anode and a cathodein communication with the polymeric film and a voltage source inelectrical communication with the electrodes.

The remaining components, although important, are not critical. One suchimportant component is the substrate. A substrate, when included in theLED, is utilized as a support to deposit the polymeric film lightemitting layer. Obviously, optical characteristics of the substratematerial are important. Optical transparency of the substrate permitsviewing of emitted light in a direction perpendicular to the plane ofthe light emitting polymeric film. However, optical transparency of thesubstrate is not essential. As those skilled in the art are aware,optical transparency is not required where an integrated optics oroptical interconnection of electronic devices, where the emitted lightis guided to a waveguide, is not employed. In such case, the refractiveindex of the substrate material must be significantly different fromthat of the polymer or the waveguide. Independent of its opticalproperties, the substrate should be rigid if employed in a flat paneldisplay but must be flexible if used in a curved panel display.

As depicted in the drawings illustrating preferred light emittingdiodes, the substrate may be provided with a conducting electrodesurface. The conducting electrode surface is deposited upon thesubstrate. Among preferred conducting electrode surfaces deposited upona substrate are metals, indium tin oxide, polyaniline, an ion implantedpolymer of one of the polymers within the contemplation of thosepolymers useful as the polymeric film of the present invention and thelike. It is emphasized that these materials, other than a metalliclayer, are optically transparent permitting emitted light to passtherethrough. In the preferred embodiment wherein a metallic layer isutilized, the thickness of the layer is deliberated provided in a layerso thin that it is not light opaque, permitting emitted light to passtherethrough.

The substrate itself is preferably glass or a polymer. Particularlypreferred polymers for use as the substrate are such transparentplastics as polycarbonate or poly(methylmethacrylate). These substratesare provided in the form of films.

As noted earlier, many of the polymeric films utilized in the lightemitting diode of the present invention are ion implanted. The ionimplanted films utilized in the light emitting device of the presentinvention are transparent in the visible range.

In regard to the ion implantation of the polymeric film, it has beensurprisingly found that both n-type and p-type conductivity by means ofion implantation is obtainable. Ions of inert elements including helium,neon, argon, xenon and krypton may be ion implanted to provide eithern-type or p-type ion implantation. Of these, argon, krypton and xenonare preferred, especially to provide an n-type ion implantation layer.The halogen elements, fluorine, chlorine, bromine and iodine areemployable to provide ion implantation albeit only in forming a p-typeion implanted electrically conductive layer. Elements of the alkalinemetals, lithium, sodium and potassium, are particularly preferred toprovide an n-type ion implantation layer.

The metal cathode utilized in these devices are preferably calcium,indium or aluminum. The metal of the anode is preferably gold orplatinum. It is particularly preferred that the metal cathode be calciumand the metal anode be gold.

It is noted that ion implanted polymeric films require less film-metalelectrode contact than non-ion implanted films. Thus, polymeric filmswhich are free of ion implantation usually require complete surfacecontact with a metal electrode. On the other hand, smaller electrodes,providing much less contact with the polymeric surface, may be usedwhere electrode contact is with an ion implant layer of the polymericfilm.

The polymeric light emitting diodes employing π-conjugated polymersdescribed herein are preferably prepared by film extrusion, in the caseof free standing films, or by spin coating the polymer onto a substrate,in the case of supported films. Spin coating involves coating a solutionof the polymer, preferably in a nitroalkane/Lewis acid solvent.Polymeric films produced by spin coating typically have a thickness inthe range of between about 20 nm to 5 microns and are not oriented.Extruded films, utilized in free standing films, are oriented and have athickness in excess of one micron.

The electrodes, in electrical communication with the polymeric film, aremetals of the type mentioned above which are preferably vacuumevaporated onto the surface of the polymeric film to which they are inelectrical communication.

The following examples are given for illustrative purposes only andshould not be taken as forming a limitation of any sort on the scope ofthe present invention.

EXAMPLE 1-35

Examples 1-35 are directed to the preparation of π-conjugated polymersfalling within the scope of Formulae VI and VII, which generally relateto polyanthrazoles and polyquinolines, respectively, and copolymerscomprising repeating units of these formulae. In the preparation ofthese polymers the following materials referred to herein were preparedor obtained as indicated below or otherwise set forth in the examples.

The following monomers were prepared as indicated:3,3'-dibenzoylbenzidine was synthesized as set forth in Macromolecules(1981) 14, 493-502 and Macromolecules (1990) 23, 2418-2422.2,5-dibenzoyl-1,4-phenylenediamine was synthesized as set forth in J.Polym. Sci., Polym. Chem. Ed., (1975) 13, 2233-2249; 5-acetyl-2-aminobenzophenone was synthesized as set forth in J. Heterocycl. Chem. (1974)11, 107-111; Diacetylstilbene was synthesized as set forth inMacromolecules (1985) 18, 321-327; 5,5'-Diacetylbiphenylacetylene wassynthesized as set forth in Macromolecules (1986) 19, 257-266;Hex-3-ene-2,4-dione was synthesized as set forth in Bull. Soc. Chim. Fr.1957, 997-1003. Hex-3-yne-2,4-dione was synthesized as set forth in J.Chem. Soc., Perkin Trans. I (1987) 1579-1584; 2,5-diacetylthiophene wassynthesized as set forth in J. Org. Chem. (1982) 47, 3027-3038.Di-m-cresyl-phosphate (DCP) was synthesized as set forth in J. Polym.Sci., Polym. Symp., 1978, 65, 41-53.

4,4'-diacetyl-1,1'-biphenylene (methanol), 1,4-diacetylbenzene(benzene), and 4,4-diacetyldiphenylmethane (toluene) were obtainedcommercially and purified by recrystallization. All other materials wereused as obtained: dibenzyl phosphate (Aldrich); diethyl dithiophosphate(Aldrich); bis(2-ethylhexyl) hydrogen phosphate (Aldrich); diphenylphosphate (Aldrich); triphenyl phosphate (Aldrich); AlCl₃ (Aldrich);GaCl₃ (Sigma); triethylamine (Baker).

EXAMPLE 1 Preparation of the Monomer 1,2-Bis(5-acetyl-2-thienyl)ethylene

To a slurry of 1 g tetrakis(triphenyl phosphine)Palladium (0) in 30 mlof dry toluene was added a solution of 6.6 g (32.2 mmol) of2-acetyl-5-bromo thiophene in 30 ml of dry toluene under argon. Thelight brown solution so obtained was heated to reflux. To this solutionwas added dropwise a solution of 9.8 g (16.1 mmol) of(E)-1,2-bis(tri-n-butyl stannyl) ethylene, as described in Dokl. Akad.Nauk. SSSR 174, 96, (1967) in 50 ml of toluene (dry) over a period of1.5 h. After refluxing the reaction mixture for another 5.5 h, it wasslowly cooled down to -5° C., and the yellow product was isolated bysuction filtration. The product was washed with hexane to remove most ofthe tri-n-butyltin bromide and dried before it was recrystallized fromchloroform. On drying in a vacuum oven at 60° C. for 24 hr., a yield of3.23 g (72.6%) having the following characteristics was obtained. mp247.6° C.; UV/vis λ_(max) (CHCl₃): 413 (log ε=4.54), 392 (4.66); FT-IR(KBr, cm⁻¹): 3070, 3014, 1655, 1646, 1528, 1459, 1423, 1363, 1276, 1263,1224, 1075, 1032, 983, 929, 805, 747, 714, 655, 612, 592, 578, 500, 480;¹ H NMR (CD₂ Cl₂, 300 MHz, TMS) δ 2.53 (s,6H), 7.15 (d,2H), 7.21 (s,2H),7.60 (d,2H). Anal. calc. for C₁₄ H₁₂ S₂ : C, 60.84, H, 4.38; N, 0.0.Found: C, 60.55; H, 4.22; N, 0.0.

EXAMPLE 2 Preparation of the Monomer 5,5'-Diacetyl-2,2'-bithiophene

To a slurry of 1 g tetrakis(triphenyl phosphine) Palladium (0) in 30 mlof dry toluene was added a solution of 6.26 g (30.5 mmol) of2-acetyl-5-bromo thiophene in 30 ml of dry toluene under argon. Thereaction was heated to reflux and to this solution was added dropwise asolution of 5 g (15.26 mmol) of hexamethylditin (99%) in 50 ml toluene(dry) over a period of 1.5 h. The reaction mixture was refluxed foranother 6 h and then cooled down to -5° C. Light yellow crystals of theproduct were isolated by suction filtration and were washed with hexane.The product was then continuously extracted through Whatman filter paper#42 with dioxane using a soxhlet apparatus until all of the product wasdissolved and collected in the boiling flask. Slow cooling of thedioxane solution resulted in needle shaped light yellow crystals of themonomer which were separated by suction filtration and dried in vacuum.A Yield of 2.56 g (67%) having the following characteristics wasobtained: mp 235° C. (lit. mp 233.5°-234° C.); UV/vis λ_(max) (CHCl₃):367 (log ε=4.19), 262 (3.57); FT-IR (KBr,cm⁻¹): 3070, 1797 1656, 1611,1511, 1433, 1361, 1302, 1270, 1089, 1036, 1020, 937, 897, 881, 792, 745,673, 611, 593, 555, 463, 442; ¹ H NMR (CDCl₃ 300 MHz, TMS) δ 2.58(s,6H), 7.30 (d,2H), 7.62 (d,2H). Anal. calcd. for C₁₂ H₁₀ S₂ : C,57.58; H, 4.03; N, 0.0. Found: C, 57.48; H, 3.87; N, 0.0.

EXAMPLE 3 Preparation of the Monomer1,2-Bis(5-acetyl-2-thienyl)acetylene

To a slurry of 1 g tetrakis(triphenyl phosphine) Palladium (0) in 30 mlof dry toluene was added a solution of 6.6 g (32.2 mmol) of2-acetyl-5-bromo thiophene in 30 ml of dry toluene under argon. Thelight brown solution so obtained was heated to reflux. To this solutionwas added dropwise a solution of 9.8 g (16.1 mmol) of1,2-bis(tri-n-butylstannyl)acetylene in 50 ml of toluene (dry) over aperiod of 2 h. After refluxing the reaction medium for another 6 h, itwas cooled down to -5° C., and the yellow product was isolated bysuction filtration. The product was washed with hexane to remove most ofthe tri-n-butyltin bromide. The product was then continuously extractedthrough Whatman filter paper #42 with dioxane using a soxhlet apparatusuntil all of the product was dissolved and collected in the boilingflask. Slow cooling of the dioxane solution resulted in needle shapedlight yellow crystals of the monomer which were separated by suctionfiltration and dried in vacuum at 60° C. for 24 h. A yield of 2.56 g(65%) having the following characteristics was obtained: mp 214° C.;UV/vis λ_(max) (CHCl₃): 387 (log ε=4.25), 362 (4.31), 281 (3.78); IR(Nujol, cm-1): 3070, 1670, 1390, 1295, 1260, 1045, 945, 910, 820; ¹ HNMR (CD2Cl2, 300 MHz, TMS) δ 7.60 (d, 2H), 7.33 (d,2H), 2.55 (s,6H).

EXAMPLE 4 Preparation ofPoly(2,2'-(p,p'-biphenylacetylene)-6,6'-bis(4-phenylquinoline)) (PBAPQ)

Equimolar amounts (3.82 mmol each) of both 3,3'-dibenzoylbenzidine and5,5'-diacetyl biphenylacetylene were added to a solution of 25 g ofdi-m-cresyl phosphate (DCP) and 9 g of freshly distilled m-cresol in acylindrical shaped reaction flask (glass) fitted with a mechanicalstirrer, two gas inlets, and a side arm. The reactor was purged withargon for 10-15 min. before the temperature was raised slowly to140°-142° C. in 2-3 h. As the viscosity of the reaction mixtureincreased with time, small amounts of m-cresol were added to thereaction mixture to facilitate efficient stirring. The reaction wasmaintained at this temperature for 48 h under static argon. Thereafterthe reaction was quenched by cooling it down to room temperature underargon and precipitating it in 500 ml of 10% triethylamine/ethanolmixture. The precipitated polymer was then chopped in a blender andcollected by suction filtration. The polymer was purified by continuousextraction in soxhlet apparatus with 20% triethylamine/ethanol solutionfor 36 h and was dried in vacuum at 80° C. for 24 h. The PBAPQ polymerobtained had the following characteristics: [η]=8.9 dL/g (25° C., 0.1mol % DCP/m-cresol); FT-IR (freestanding film, cm⁻¹): 3057, 3036, 1586,1575, 1538, 1519, 1488, 1455, 1410, 1358, 1234, 1181, 1153, 1110, 1065,1016, 874, 840, 828, 786, 771, 735, 701, 622, 588; Anal. calcd. for (C₄₄H₂₆ N₂)_(n) : C, 90.70; H, 4.50; N, 4.84. Found: C, 88.87; H, 4.49; N,4.69.

EXAMPLE 5 Preparation ofPoly(2,2'-(4,4'-diphenylmethane)-6,6'-bis(4-phenylquinoline)) (PDMPQ)

PDMPQ was synthesized using the procedure described in Example 4 usingequimolar amounts (1.78 mmol each) of 3,3'-dibenzoylbenzidine (18) anddiacetyldiphenylmethane as the two monomers. 15 g of diphenyl phosphatewith 8 g of m-cresol was used as the reaction medium instead ofDCP/m-cresol. The PDMPQ polymer obtained had the followingcharacteristics: [η]=9.3 dL/g (25° C., 0.1 mol % DCP/m-cresol); FT-IR(freestanding film, cm⁻¹): 3056, 3028, 1585, 1572, 1541, 1486, 1427,1353, 1230, 1182, 1152, 1065, 1017, 910, 826, 761, 700, 587; Anal.calcd. for (C₄₃ H₃₃ N₂)_(n) : C, 90.18; H, 4.93; N, 4.89. Found: C,85,34; H, 4.51; N, 4.58.

EXAMPLE 6 Preparation ofPoly(2,7-(p,p'-biphenylacetylene)-4,9-diphenyl-1,6-anthrazoline) (PBADA)

PBADA was synthesized and isolated according to the procedure describedin Example 4 using equimolar amounts (2.21 mmol each) of the monomers2,5-dibenzoyl-1,4-phenylenediamine and diacetylbiphenylacetylene asreactants which were added to a mixture of 15 g of DCP and 8 g ofm-cresol. The PBADA polymer obtained had the following characteristics:[η]=7.65 dL/g (25° C., 0.1 mol % DCP/m-cresol); FT-IR (freestandingfilm, cm⁻¹): 3037, 2967, 1590, 1558, 1519, 1492, 1453, 1408, 1351, 1288,1238, 1181, 1052, 1016, 970, 894, 840, 765, 699, 539; Anal. calcd. for(C₃₈ H₂₂ N₂)_(n) : C, 90.09; H, 4.38; N, 5.53. Found: C, 86.92; H, 4.20;N, 5.23.

EXAMPLE 7 Preparation ofPoly(2,7-(p,p'-stilbene)-4,9-diphenyl-1,6-anthrazoline) (PSDA)

PSDA was synthesized and isolated according to the procedure describedin Example 6 using equimolar amounts (2.21 mmol each) of2,5-dibenzoyl-1,4-phenylenediamine and diacetylstilbene as reactants.The PSDA polymer obtained had the following characteristics: [η]=30.3dL/g (25° C., 0.1 mol % DCP/m-cresol); FT-IR (freestanding film, cm⁻¹):3028, 2966, 1733, 1590, 1572, 1492, 1453, 1415, 1349 1238, 1181, 1148,1053, 1015, 969, 894, 840, 765, 699, 533; Anal. calcd. for (C₃₈ H₂₄N₂)_(n) : C, 89.74; H, 4.76; N, 5.51. Found: C, 85.66; H, 4.55; N, 5.32.

EXAMPLE 8 Preparation ofPoly(2,7-(4,4'-diphenylmethane)-4,9-diphenyl-1,6-anthrazoline) (PDMDA)

PDMDA was synthesized and isolated according to the procedure describedin Example 4 using equimolar amounts (2.21 mmol each) of2,5-dibenzoyl-1,4-phenylenediamine and diacetyldiphenylmethane asreactants in a reaction medium of 15 g DPP and 11.5 g m-cresol. Thepolymer obtained was worked up as usual. The PDMDA polymer obtained hadthe following characteristics: [η]=0.87 dL/g (25° C., 0.1 mol %DCP/m-cresol); FT-IR (freestanding film, cm⁻¹): 3027, 1588, 1566, 1528,1510, 1490, 1451, 1433, 1412, 1363, 1344, 1276, 1234, 1180, 1147, 1110,1074, 1051, 1030, 1016, 969, 893, 816, 761, 697; Anal. calcd. for (C₃₇H₂₄ N₂)_(n) : C, 89.49; H, 4.87; N, 5.64. Found: C, 87.34; H, 4.68; N,5.40.

EXAMPLE 9 Preparation ofPoly(2,2'-(2,2'-bithiophenyl)-6,6'-bis(4-phenylquinoline)) (PBTPQ)

PBTPQ was synthesized isolated according to the procedure described inExample 4 using equimolar amounts (1.27 mmol each) of3,3'-dibenzoylbenzidine and 5,5'-diacetyl-2,2'-bithiophene preparedaccording to the procedure described in Example 2, as reactants whichwere mixed with 12 g DCP and 2 g m-cresol. The PBTPQ polymer obtainedhad the following characteristics: [η]=11.5 dL/g (25° C., 0.1 mol %DCP/m-cresol); FT-IR (freestanding film, cm⁻¹): 3063, 2967, 1586, 1543,1519, 1489, 1454, 1442, 1360, 1282, 1225, 1076, 871, 823, 787, 767, 701,621, 590; anal. calcd. for (C₃₈ H₂₂ N₂ S₂)_(n) : C, 79.97; H, 3.89; N,4.91. Found: C, 78.27; H, 3.89; N, 4.77.

EXAMPLE 10 Preparation ofPoly(2,2'-(2-thienylethynyl-2-thienyl)-6,6'-bis(4-phenylquinoline))(PBTAPQ)

PBTAPQ was synthesized and isolated according to the procedure describedin Example 4 using equimolar amounts (1.27 mmol each) of3,3'-dibenzoylbenzidine and 1,2-Bis(5-acetyl-2-thienyl)acetyleneprepared according to the procedure described in Example 3 were mixedwith 12 g DCP and 2 g m-cresol. The PBTAPQ polymer obtained had thefollowing characteristics: FT-IR (freestanding film, cm⁻¹): 3059, 2969,1740, 1590, 1544, 1489, 1465, 1359, 1304, 1243, 1149, 1069, 1030, 970,874, 825, 768, 701, 585; Anal. calcd. for (C₄₀ H₂₂ N₂ S₂)_(n) : C,80.78; H, 3.73; N, 4.71. Found: C, 77.04; H, 4.12; N, 4.13. Intrinsicviscosity was not determined.

EXAMPLE 11 Preparation ofPoly(2,2'-(2-thienylethenyl-2-thienyl)-6,6'-bis(4-phenylquinoline))(PBTVPQ)

PBTVPQ was synthesized and isolated according to the procedure describedin Example 4 using equimolar amounts (1.27 mmol each) of3,3'-dibenzoylbenzidine and 1,2-Bis(5-acetyl-2-thienyl)ethylene preparedaccording to the procedure described in Example 1, as reactants whichwere mixed with 12 g DCP and 2 g m-cresol. The polymer PBTVPQ obtainedhad the following characteristics: [η]=6.2 dL/g (25° C., 0.1 mol %DCP/m-cresol); FT-IR (freestanding film, cm⁻¹): 3060, 2968, 1586, 1545,1473, 1360, 1259, 1238, 1066, 1029, 932, 874, 825, 768, 701, 621, 586;Anal. calcd. for (C₄₀ H₂₄ N₂ S₂)_(n) : C, 80.51; H, 4.05; N, 4.69.Found: C, 78.02; H, 4.22; N, 4.71.

EXAMPLE 12 Preparation ofPoly(2,2'-(2,5-thiophenyl)-6,6'-bis(4-phenylquinoline)) (PTPQ)

PTPQ was synthesized and isolated according to the procedure describedin Example 4 using equimolar amounts (1.78 mmol each) of3,3'-dibenzoylbenzidine and 2.5-diacetyl thiophene as reactants in 16.5g DCP and 2 g m-cresol. The PTPQ polymer obtained had the followingcharacteristics: [η]=10.5 dL/g (25° C., 0.1 mol % DCP/m-cresol); FT-IR(freestanding film, cm⁻¹): 3057, 2967, 1586, 1544, 1489, 1451, 1362,1235, 1150, 1075, 1030, 872, 846, 824, 767, 701, 623, 570; Anal. calcd.for (C₃₄ H₂₀ N₂ S₁)_(n) : C, 83.58; H, 4.13; N, 5.73. Found: C, 81.31;H, 4.02; N, 5.55.

EXAMPLE 13 Preparation ofPoly(2,7-(2,2'-bithiophenyl)-4,9-diphenyl-1,6-anthrazoline) (PBTDA)

Equimolar amounts of both 2,5-dibenzoyl-1,4-phenylenediamine (0.5 g) and5,5'-diacetyl-2,2'-bithiophene (0.3957 g), prepared according to theprocedure described in Example 2, were added along with 15 g of diphenylphosphate (DPP) and 2 g of freshly distilled m-cresol in a glass reactorfitted with mechanical stirrer, two gas inlets, and a side arm. Thereaction mixture was purged with argon for 15 min., and then thetemperature was slowly raised in steps to 140° C. under positivepressure of argon. The temperature was maintained for 48 h, during whichtime small amounts of m-cresol were added to facilitate efficientstirring of the reaction mixture whenever it became highly viscous.After cooling, the polymerization dope was slowly poured into thestirred solution of 55 mL of ethanol/500 mL of triethylamine (TEA). Theprecipitated polymer was then chopped in a blender and collected bysuction filtration. The polymer was purified by continuously extractingit with 20% TEA/ethanol solution for 24-36 h and was dried in vacuum at80° C. The PBTDA obtained had the following characteristics: [η]=2.3dL/g (25° C. 1.5 mol % DCP/m-cresol); IR (freestanding film, cm⁻¹) 3055,2964, 1588, 1527, 1492, 1442, 1425, 1358, 1274, 1232, 1074, 1030, 892,794, 765, 700, 613, 549. Anal. Calcd. for (C₃₂ H₁₈ N₂ S₂)_(n) : C, 77.7;H, 3.67; N, 5.66. Found: C, 75.76; H, 3.59; N, 5.34.

EXAMPLE 14 Preparation ofPoly(2,7-(2,2'-thienylethynyl-2-thienyl)-4,9-diphenyl-1,6-anthrazoline)(PBTADA)

PBTADA polymer was prepared using equimolar amounts of2,5-dibenzoyl-1,4-phenylenediamine (0.5 g) and1,2-bis(5-acetyl-2-thienyl)acetylene (0.4336 g), prepared according tothe procedure described in Example 3 in di-m-cresyl phosphate (DCP) asthe solvent medium instead of DPP. The same procedure as described inExample 13 was used for the polymerization. The PBTADA polymer obtainedhad the following characteristics: [η]=4.4 dL/g (25° C., 0.1 mol %DCP/m-cresol); IR (free-standing film, cm⁻¹) 3055, 2971, 1589, 1530,1492, 1445, 1427, 1355, 1290, 1240, 1063, 1030, 894, 807, 766, 701, 614,546. Anal. Calcd. for (C₃₄ H₁₈ N₂ S₂)_(n) : C, 78.74; H, 3.50; N, 5.40.Found: C, 76.82; H, 4.03; N, 4.66.

EXAMPLE 15 Preparation ofPoly(2,7-(2,2'-thienylethenyl-2-thienyl)-4,9-diphenyl-1,6-anthrazoline)(PBTVDA)

PBTVDA was synthesized and isolated according to the procedure describedin Example 13 using equimolar amounts (1.58 mmol each) of2,5-dibenzoyl-1,4-phenylenediamine and1,2-Bis(5-acetyl-2-thienyl)ethylene prepared according to the proceduredescribed in Example 1, as reactants which were reacted in 12 g DCP and2.5 g m-cresol. The PBTVDA polymer obtained had the followingcharacteristics: [η]=4.4 dL/g (25° C., 0.1 mol % DCP/m-cresol); IR(freestanding film, cm⁻¹): 3060, 2968, 1588, 1574, 1532, 1492, 1475,1357, 1289, 1259, 1239, 1146, 1061, 1030, 959, 934, 895, 796, 765, 748,702, 616, 545; Anal. calcd. for (C₃₄ H₂₀ N₂ S₂)_(n) : C, 78.43; H, 3.87;N, 5.38. Found: C, 77.38; H, 3.83; N, 5.09.

EXAMPLE 16 Preparation ofPoly(2,7-(2,5-thiopheneyl)-4,9-diphenyl-1,6-anthrazoline) (PTDA)

PTDA was synthesized and isolated according to the procedure describedin Example 15 using equimolar amounts (1.58 mmol each) of2,5-dibenzoyl-1,4-phenylenediamine and 2,5-diacetylthiophene asreactants. The PTDA polymer obtained had the following characteristics:[η]=1.2 dL/g (25° C., 0.1 mol % DCP/m-cresol); FT-IR (freestanding film,cm⁻¹): 3056, 3028, 1586, 1571, 1529, 1491, 1432, 1354, 1234, 1042, 1030,892, 851, 805, 763, 698, 616, 587; Anal. calcd. for (C₂₈ H₁₆ N₂ S₁)_(n): C, 81.53; H, 3.91; N, 6.79. Found: C, 78.68; H, 3.83; N, 6.29.

EXAMPLE 17 Preparation of the Copolymer PBPQ/PBAPQ

1.27 mmoles of 4,4'-diacetyl-1,1'-biphenylene; 1.27 mmoles of5,5'-diacetylbiphenylacetylene, and 2.55 mmole of3,3'-dibenzoylbenzidine were mixed together in a reaction medium of 17 gDCP and 16 g/m-cresol. Synthesis and isolation of the copolymer wascarried out as described in Example 4. The copolymer obtained had thefollowing characteristics: [η]=25 dL/g (25° C., 0.1 mol % DCP/m-cresol);FT-IR (freestanding film, cm⁻¹): 3057, 3033, 2960, 1586, 1539, 1488,1457, 1357, 1233, 1151, 1154, 1068, 1016, 1004, 872, 827, 771, 701, 623,590.

EXAMPLE 18 Preparation of the Copolymer PBAPQ/PSPQ

1.27 mmoles of 4,4'-diacetylstilbene, 1.27 mmoles of5,5'-diacetylbiphenylacetylene, and 2.55 mmole of3,3'-dibenzoylbenzidine were mixed together in a reaction medium of 17 gDPP and 15 g m-cresol. Synthesis and isolation of the copolymer wascarried out as described in Example 4. The copolymer obtained had thefollowing characteristics: [η]=14.3 dL/g (25° C., 0.1 mol %DCP/m-cresol); FT-IR (freestanding film, cm⁻¹): 3057, 3030, 2960, 1586,1575, 1539, 1488, 1460, 1357, 1235, 1181, 1065, 1015, 828, 771, 701,588.

EXAMPLE 19 Preparation of the Copolymer PSPQ/PBPQ

1.27 mmole of 4,4'-diacetylstilbene, 1.27 mmole ofdiacetyl-1,1'-biphenylene and 2.55 mmol of 3,3'-dibenzoylbenzidine weremixed together in a reaction medium of 17 g DCP and 16 g m-cresol. Thereaction was carried out as described in Example 4. The polymer obtainedwas worked up as usual. [η]=22.6 dL/g (25° C., 0.1 mol % DCP/m-cresol);FT-IR (freestanding film, cm⁻¹): 3057, 3029, 2960, 1586, 1574, 1540,1488, 1457, 1357, 1234, 1182, 1068, 1004, 870, 827, 772, 743, 701, 590.

EXAMPLE 20 Preparation of 5-Bromo-2-(trifluoroacetamido) Benzophenone(hereafter "Compound 1")

To a solution of 17 g (61.6 mmol) of 2-amino-5-bromo benzophenone in 556ml of diethyl ether (anhydrous) was added 64.3 g (0.61 mol) of anhydroussodium carbonate. The mixture was cooled in an ice-bath and trifluoroacetic anhydride was added dropwise as rapidly as possible to maintainat the most a gentle reflux. The reaction mixture was removed from theice-bath and stirred for 30 min. at room temperature. The white slurrywas separated between 700 ml of water and 700 ml of methylene chloride.After removing the aqueous phase, the organic phase was washed twicewith water and dried over MgSO₄. Removal of the solvent gas 22.3 g(97.4% yield) of off-white solid. mp °C.; ¹ H NMR (CDCl₃, 300 MHz) d:7.54-7.59 (m,2H), 7.66-7.80 (m,5H), 8.55 (d,1H), 11.89 (br. s, 1H).

EXAMPLE 21 Preparation of1,2-Bis(trifluoroacetamido)-3,3'-dibenzoyldiphenyl-1-1'-acetylene(Hereafter "Compound 2")

To a mixture of 22 g (59.1 mmol) of Compound 1 in 220 ml of dry toluenewas added a mixture of 1 g of tetrakis(triphenyl phosphine)palladium (0)in 50 ml of dry toluene under argon. The light brown solution soobtained was heated to reflux and to this solution was added dropwise asolution of 17.9 g (29.6 mmol) of bis(tri-n-butylstannyl)acetylene in 92ml of dry toluene. On completion of the addition, the reaction wasrefluxed for an additional 10 h. The reaction was cooled to -5° C. andyellow product isolated was by suction filtration followed by drying.Crude yield 14.5 g (80%). The product was purified by recrystallizationfrom 300 ml of tetrahydrofuran. Yield 13.2 g (73%). mp 253.8° C.; ¹ HNMR (CDCl₃, 300 MHz) d: 7.53-7.58 (m,4H), 7.66-7.81 (m,10H), 8.65(d,2H), 12.04 (br,s,2H); Anal. calcd. for C₃₂ H₁₈ N₂ O₄ F₆ : C, 63.16;H, 2.98; N, 4.60. Found: C, 62.84; H, 2.79; N, 4.55.

EXAMPLE 22 Preparation of4,4'-Diamino-3,3'-dibenzoyldi-phenyl-1,1'-acetylene (Hereafter "Compound3")

A mixture of 13 g (21.4 mmol) of Compound 2, 425 ml of degassed ethanol,105.3 ml of water and 19.15 g (0.181 mol) of anhydrous sodium carbonatewas refluxed for 72 h. The yellow slurry was cooled to room temperature,and the product was separated by filtration. After washing the producttwice with water and then with a little methanol, it was dried in vacuumat 70° C. for 24 h. Crude yield 8.66 g (97.3%). The product was purifiedby continuously extracting it in dioxane using a soxhlet apparatus (witha double thickness thimble lined with Whatman #42 filter paper) untilall of the product was dissolved and recrystallized in the boilingflask. The pure product was recovered by suction filtration, washed withhexane and methanol and dried in vacuum at 60° C. for 24 h. Yield 7.5 g(84%). mp 310.1° C.; FT-IR (KBr, cm⁻¹): 3457, 3338, 1630, 1619, 1578,1545, 1488, 1445, 1417, 1381, 1326, 1306, 1290, 1245, 1170, 1135, 975,911, 880, 831, 807, 758, 712, 706, 659, 552; Anal. calcd. for C₂₈ H₂₀ N₂O₂ : C, 80.75; H, 4.84; N, 6.73. Found: C, 80.53; H, 4.71; N, 6.46.

EXAMPLE 23 Preparation of 3-(p-methoxyphenyl)-5-bromo-2,1-benzisoxazole(Hereafter "Compound 4")

To a solution of 148 g of potassium hydroxide in 300 ml of anhydrousmethanol at 0° C. was added 21.3 g (0.145 mole) of 4-methoxyphenylacetonitrile. The mixture was stirred at 0° C. for 10 min. andthen a solution of 25.4 g (0.126 mol) of p-bromo nitrobenzene in 300 mlof tetrahydrofuran and methanol (1:2) was slowly added over a period of1 h. The deep purple mixture was continuously stirred and maintained at0°-5° C. during addition. The temperature was then raised to 55° C.using a hot water bath and reaction mixture was stirred for another 3 h.On cooling, the reaction mixture was poured into 1500 ml of water, andthe brown precipitate was separated by suction filtration. The productwas washed twice with water followed by cold methanol. The yellow solidso obtained was recrystallized twice from methanol to give needle likelight yellow crystals. Yield 19.5 g (51%). mp 137.1° C. Anal. calcd. forC₁₄ H₁₀ NO₂ Br: c, 55.29; H, 3.31; N, 4.61. Found: C, 54.99; H, 3.14; N,4.62.

EXAMPLE 24 Preparation of 2-Amino-5-bromo-4'-methoxy Benzophenone(Hereafter "Compound 5")

To a solution of 19.3 g of Compound 4 in 193 ml of acetic acid (glacial)at 95° C. was added 28.95 g of iron filings and 63 ml of water in 12equal portions over a period of 3 h. The reaction was allowed to run foran additional 20 minutes after which it was cooled down to roomtemperature. This step gave a green slurry which was diluted with 1500ml of water. Yellow product was extracted from this mixture in ethylether which was then washed with sodium carbonate solution followed bywater and dried over MgSO₄. Removal of solvent gave yellow solid as theproduct which was recrystallized from methanol to give a yield of 16.6 g(85.4%). mp 120.4° C.; ¹ H NMR (CDCl₃,300 MHz) d: 3.9 (s,3H), 5.87 (br.s, 2H), 6.64 (d, 1H); 6.96 (d,2H), 7.32-7.4 (m, 1H), 7.57 (d,1H),7.65-7.75 (d,2H); Anal. calcd. for C₁₄ H₁₂ NO₂ Br: C, 54.92; H, 3.95; N,4.57. Found: C, 54.70; H, 3.74; N, 4.56.

EXAMPLE 25 Preparation of 5-Bromo-4'-methoxy-2-(trifluoroacetamido)Benzophenone (Hereafter "Compound 6")

To a solution of 16 g (52.3 mmol) of Compound 5 in 368 g of ethyl ether(dry) was added 54 g (0.515 mol) of sodium carbonate (anhydrous). Theslurry was cooled in an ice bath and 37.2 ml (0.263 mol) oftrifluoroacetic anhydride was added dropwise as rapidly as possible tomaintain at the most a gentle reflux. Thick white slurry so obtained,was stirred at room temperature for another 45 minutes and thenseparated between 500 ml of methylene chloride and 500 ml of water. Theaqueous layer was removed and organic layer was washed twice with waterbefore drying it over MgSO₄. Removal of solvent gave 21.02 g (95.5%) ofoff-white product. mp 148.9° C.; ¹ H NMR (CDCl₃,300 MHz) d: 3.93 (s,3H),7.02 (d,2H), 7.75-7.78 (m,4H), 8.49 (d, 1H), 11.66 (br. s,1H); Anal.calcd. for C₁₆ H₁₁ NO₃ BrF₃ : C, 47.79; H, 2.76; N, 3.48. Found: C,47.67; H, 2.70; N, 3.51.

EXAMPLE 26 Preparation of4-4'-Bis(trifluoroacetamido)-3-3'-di-p-methoxybenzoyldiphenyl;-1,1'-acetylene(Hereafter "Compound 7")

To a solution of 19.5 g of Compound 6 in 233 ml of dry toluene was addeda mixture of 1 g of tetrakis(triphenyl phosphine)Palladium (0) and 50 mlof dry toluene under argon. The mixture was heated to reflux, and to itwas added dropwise a solution of 14.6 g (24.2 mmol) of bis(tri-n-butylstannyl)acetylene in 76.5 ml of dry toluene over a period of 2 h. Thereaction was refluxed for an addition 10 h during which time part oforangish-yellow product precipitated. After cooling the reaction mixtureto -5° C., the product was isolated by suction filtration (crude yield13.03 g, 80%). The product was purified by continuously extracting it intoluene using soxhlet apparatus (with double thickness thimble linedwith Whatman #42 filter paper) until all of the product was dissolvedand collected in the boiling flask. The pure product was recovered bysuction filtration of the cold toluene mixture (at -5° C.). Yield 11 g(68%). mp 261.2° C.; ¹ H NMR (CDCl₃,300 MHz) d: 3.93 (s,6H), 7.02(d,4H), 7.75-7.80 (m,8H), 8.60 (d,2H), 11.82 (br. s, 2H); Anal. calcd.for C₃₄ H₂₂ N₂ O₆ F₆ : C, 61.08; H, 3.32; N, 4.19. Found C, 60.80; H,3.20; N, 4.19.

EXAMPLE 27 Preparation of4,4'-Diamino-3,3'-di-p-methoxybenzoyldiphenyl-1,1'-acetylene (Hereafter"Compound 8")

11 g of Compound 7 was mixed with 350 ml of degassed ethanol, 89 ml ofwater, and 15 g (0.142 mol) of sodium carbonate. The mixture wasrefluxed for 84 h. Bright yellow slurry was cooled to room temperature,filtered and the solid product dried to give crude yield of 7.7 g. Theproduct was purified by continuously extracting it in dioxane usingsoxhlet apparatus (with double thickness thimble line with Whatman #42filter paper) until all of the product was dissolved and recrystallizedin the boiling flask. Pure product was recovered by suction filtrationand dried in vacuum at 60° C. for 24 h. Yield was 6.3 g (80%). mp 235.3°C.; ¹ H NMR (CDCl₃, 300 MHz) d: FT-IR (KBr, cm⁻¹): 3457, 3345, 1624,1602, 1562, 1570, 1508, 1461, 1441, 1415, 1363, 1305, 1258, 1243, 1172,1111, 1028, 977, 957, 881, 843, 785, 695, 635, 614; Anal. calcd. for C₃₀H₂₄ N₂ O₄ : C, 75.62; H, 5.08; N, 5.88. Found: C, 75.86; H, 5.01; N,5.78.

EXAMPLE 28 Preparation of5-Bromo-2'-fluoro-2-(trifluoroacetamido)benzophenone (Hereafter"Compound 9")

To a solution of 12 g of 2 amino-5-bromo-2'-fluoro benzophenone(Lancaster) in 407 ml of dry diethylether was added 42.6 g of anhydroussodium carbonate. The reaction mixture was cooled in an ice bath, and 29ml of trifluoroacetic anhydride was added dropwise as rapidly aspossible while maintaining at the most a gentle reflux. Thereafter, theice bath was removed, and the reaction mixture was stirred for 30 min.at room temperature. The off-white reaction slurry was separated between500 ml methylene chloride and 500 ml of water. The aqueous layer wasremoved and organic layer was washed twice with water and dried overMgSO₄. Filtration and evaporation of the solvent gave 15.7 g (98.5%) ofproduct. mp 132° C.; ¹ H NMR (CDCl₃,300 MHz) d: 7.24 (t,1H), 7.35(t,1H), 7.50-7.55 (m, 1H), 7.60-7.67 (m, 1H), 7.72 (t,1H), 7.77-7.81 (dof d,1H), 8.62 (d, 1H), 12.29 (s,1 NH); Anal. calcd. for C₁₅ H₈ NO₂ BrF₄: C, 46.18; H, 2.07; N, 3.59. Found: C, 46.33; H, 1.94; N, 3.68.

EXAMPLE 29 Preparation of4,4'-Bis(trifluoroacetamido)-3-3'-di-o-fluorobenzoyldiphenyl,1,1'-acetylene(Hereafter "Compound 10")

To a solution of 15 g (38.4 mmol) of Compound 9 in 100 ml of dry toluenewas added a mixture of 1 g of tetrakis(triphenylphosphine)Palladium (0)in 50 ml of dry toluene under argon. The reaction mixture was thenheated to reflux, and to this mixture was added dropwise a solution of11.6 g (19.2 mmol) of bis(tri-n-butylstannyl)acetylene in 60 ml toluene(dry) over a period of 2 h. The reaction was refluxed for an additional10 hrs after which it was cooled down to -5° C. The yellow crystals ofproduct were isolated by suction filtration followed by washing withhexane. The crude product obtained (12.4 g) was dissolved in excesschloroform, filtered and then recrystallized from chloroform to give ayield of 7.6 g (61.1%). mp 267.2° C.; ¹ H NMR (CDCl₃,300 MHz) d: 7.24(t,2H), 7.35 (t,2H), 7.5-7.55 (m,2H), 7.59-7.67 (m,2H), 7.72 (t,2H),7.76-7.81 (d of d,2H), 8.71 (d,2H), 12.29 (s,2NH); Anal. calcd. for C₃₂H₁₆ N₂ O₄ F₈ : C, 59.64; H, 2.50; N, 4.35. Found: C, 59.24; H, 2.41; N,4.33.

EXAMPLE 30 Preparation of4,4'-Diamino-3,3'-di-o-fluorodibenzoyldiphenyl-1,1'-acetylene (Hereafter"Compound 11")

A mixture of 7.35 g (11.5 mmol) of Compound 10, 10.36 g (98 mmol) ofanhydrous sodium carbonate, 57 ml of water and 230 ml of degassedethanol was heated at reflux for 72 h. On cooling, the solid product wasseparated by suction filtration, washed with water (twice), and dried invacuum oven. Crude yield 5.05 g. The product was purified bycontinuously extracting it in chloroform using soxhlet apparatus (withdouble thickness thimble layered with Whatman #42 filter paper) untilall of the product was dissolved and recrystallized in the boilingflask. Upon cooling, the product was isolated by suction filtration anddried in vacuum oven at 60° C. for overnight. Yield was 4.24 g (82%).Compound 11 did not show any mp, exothermic peak (possibly crosslinking)starts around 290° C.; FT-IR (KBr, cm⁻¹): 3464, 3338, 1638, 1621, 1582,1545, 1485, 1450, 1420, 1364, 1329, 1307, 1289, 1270, 1245, 1218, 1172,1138, 976, 887, 830, 817, 757, 648; Anal. calcd. for C₂₈ H₁₈ N₂ O₂ F₂ :C, 74.33; H, 4.01; N, 6.19; F, 8.40. Found C, 73.98; H, 3.93; N, 6.12;F, 8.46.

EXAMPLE 31 Preparation of the PolymerPoly(2,2'-(2,2'-bithiophene)-6,6'-bis(4-phenylquinoline)acetylene(PBTPQA)

Equimolar amounts (1.2 mmol each) of both4,4'-diamino-3,3'-dibenzoyldiphenyl-1,1'-acetylene (Compound 3) and5,5'-diacetyl-2,2'-bithiophene were added to a solution of 12 g ofdi-m-cresyl phosphate (DCP) and 15 g of freshly distilled m-cresol in acylindrical shaped reaction flask (glass) fitted with a mechanicalstirrer, two gas inlets, and a side arm. The reactor was purged withargon for 10-15 min. before the temperature was raised slowly to 90° C.The reaction was run at this temperature for 24 h and then at 120°-130°C. for an additional 10 h under static argon. Thereafter the reactionwas quenched by cooling it down to room temperature under argon andprecipitating it in 500 ml of 10% triethylamine/ethanol mixture. Theprecipitated polymer was then collected by suction filtration. Thepolymer was purified by continuous extraction in soxhlet apparatus with20% triethylamine/ethanol solution for 36 h and was dried in vacuum at80° C. for 24 h. The PBTPQA polymer obtained had the followingcharacteristics: [η]=0.89 dL/g (25° C.,0.5 mol % DCP/m-cresol); FT-IR(KBr,cm⁻¹): 3050, 2910, 1584, 1542, 1490, 1457, 1438, 1361, 1290, 1229(w), 1155, 1074, 1030, 873, 835, 797, 767, 700, 619, 584; Anal. calcd.for (C₄₀ H₂₂ N₂ S₂)_(n) : C, 80.78; H, 3.73; N, 4.71. Found: C, 77.5; H,4.32; N, 3.96.

EXAMPLE 32 Preparation of the PolymerPoly(2,2'-(2,2'-bithiophene)-6,6'-bis(4-(p-methoxy)phenylquinolineAcetylene) (PBTPQA-OCH₃)

Equimolar amounts (1.2 mmol each) of both4,4'-diamino-3,3'-di-p-methoxybenzoyldiphenyl-1,1'-acetylene (Compound8) and 5,5'-diacetyl-2,2'-bithiophene were added to a solution of 12 gof di-m-cresyl phosphate (DCP) and 15 g of freshly distilled m-cresol ina reaction flask as described in Example 31. The reaction was purgedwith argon for 10-15 min. before the temperature was raised slowly to60° C. and then to 90° C. The reaction was run at 90° C. for 4 h andthen at 100° C. for addition 15 h under static argon. The temperaturewas then raised to 125°-130° C. for 5 h and then to 140° C. for 2 h. Asthe viscosity of the reaction mixture increased with time, addition atm-cresol was added to the reaction mixture to maintain dilutedconditions. Thereafter the reaction was quenched, precipitated, andpurified as described in Example 31. The PBTPQA-OCH₃ polymer obtainedhad the following characteristics: [η]=1.1 dL/g (25° C., 0.5 mol 5DCP/m-cresol); FT-IR (KBr, cm⁻¹): 3055, 2914, 1649, 1608, 1583, 1541,1511, 1453, 1439, 1400, 1362, 1291, 1248, 1176, 1031, 832, 798, 573;Anal. calcd. for (C₄₂ H₂₆ N₂ O₂ S₂)_(n) : C, 77.04; H, 4.00; N, 4.28.Found: C, 74.27; H, 4.51; N, 3.60.

EXAMPLE 33 Preparation of the polymerPoly(2,2'-(2,2'-bithiophene)-6,6'-bis(4-(o-fluoro)phenylquinolineacetylene) (PBTPAQA-F)

Equimolar amounts (0.663 mmol each) of both4,4'-diamino-3,3'-di-o-fluorodibenzoyldiphenyl-1,1'-acetylene (Compound11) and 5,5'-diacetyl-2,2'-bithiophene were reacted as described inExample 31. The polymer product was collected and purified as describedin Example 31. The PBTPAPQ-F polymer obtained had the followingcharacteristics: [η]=0.65 dL/g (25° C., 0.5 mol % DCP/m-cresol); FT-IR(KBr,cm⁻¹): 1616, 1585, 1543, 1518, 1487, 1447, 1433, 1358, 1290, 1270,1227 (s), 1156, 1100, 1064, 1032, 877, 835, 799, 758, 619, 589; Anal.calcd. for (C₄₀ H₂₀ N₂ S₂ F₂)_(n) : C, 76.17; H, 3.2; N, 4.44. Found: C,74.66; H, 3.87; N, 3.72.

EXAMPLE 34 Preparation of the Copolymer PBTPQ/PBTPQA-OCH₃ (Molar Ratioof 80:20), Respectively

0.255 mmole of4,4'-diamino-3,3'-di-p-methoxybenzoyldiphenyl-1,1'-acetylene (Compound8), 1.02 mmol of 3,3'-dibenzoylbenzidine and 1.275 mmol of5,5'-diacetyl-2,2'-bithiophene were mixed together in a reaction mediumof 12 g DCP and 2 g m-cresol. After the reactor was purged with argonfor 10-15 min., the temperature was raised slowly to 90° C. The reactionwas run at this temperature for 9 h and then at 110° C. for 15 hfollowed by 135°-140° C. for addition 24 h under static argon. As theviscosity of the reaction mixture increased with time, additionalm-cresol was added to the reaction mixture to facilitate efficientstirring. Thereafter the reaction was quenched, precipitated andpurified as described in Example 31.

EXAMPLE 35 Preparation of the Copolymer PBTPQ/PBTPQA-F (Molar Ratio of80:20), Respectively

0.255 mmole of4,4'-diamino-3,3'-di-o-fluorodibenzoyldiphenyl-1,1'-acetylene (Compound11), 1.02 mmol of 3,3'-dibenzoylbenzidine and 1.275 mmol of5,5'-diacetyl-2,2'-bithiophene were mixed together in a reaction mediumof 12 g DCP and 2 g m-cresol. The reactor was purged with argon for10-15 min. before the temperature was raised slowly to 90° C. Thereaction was run at this temperature for 2 h and then at 100° C. for 3 hfollowed by 130° C. for additional 25 h under static argon. As theviscosity of the reaction mixture increased with time, additionalm-cresol was added to the reaction mixture to facilitate efficientstirring. Thereafter the reaction was quenched, precipitated, andpurified as described in Example 31.

EXAMPLES 36-50

Examples 36-50 are directed to the preparation of π-conjugated polymersfalling within the scope of Formulae I-IV, which generally relate topolybenzobisazoles.

EXAMPLE 36 Preparation of Polybenzobisimidazole

1,2,4,5-tetraminobenzene tetrahydrochloride (TABH) (4.0 g, 14.18 mmol)was dissolved in 77% polyphosphoric acid (PPA) (12 g). The 77% PPA wasprepared by combining polyphosphoric acid and 85% phosphoric acid. Thethus formed solution of TABH in PPA was placed in a glass reactor fittedwith a mechanical stirrer, two gas ports and a side arm. The reactionvessel was purged with nitrogen for 20 minutes and thereupon maintainedat a temperature of 80° C. under vacuum for 24 hours. After thistreatment, complete dehydrochlorination occurred and the reactionmixture was cooled to 50° C. under a nitrogen atmosphere.

Oxalic acid (1.277 g, 14.18) and phosphorus pentoxide (P₂ O₅) (8 g), theP₂ O₅ to compensate for the calculated water of condensation, was addedto the dehydrochlorinated product. The reaction temperature was raisedto 120° C. and held at this temperature for 10 hours. The reactiontemperature was thereupon raised to 140° C. and finally to a range of180° to 200° C. The reaction was allowed to proceed in this elevatedtemperature range of 180° to 200° C. for 36 hours.

The resultant product, a polymerization dope in PPA, blue-green incolor, was cooled to room temperature and precipitated in water. Theproduct was thereupon purified by extraction of the PPA with water forthree days.

The thus prepared product, polybenzobisimidazole (PBBI), wascharacterized by Fourier Transfer Infrared (FTIR) as follows:

FTIR (KBr pellet, cm⁻¹) 3408, 3010, 1616, 1512, 1447, 356, 1256, 1179,1139, 1069, 841.

EXAMPLE 37 Preparation of Poly(benzobisimidazole Vinylene)

TABH (5.2 g 18.3 mmol) was dehydrochlorinated in deaerated 77% (PPA)(16.5 g) in accordance with the procedure utilized in Example 1. Uponcomplete dehydrochlorination, and under the conditions present inExample 1, fumaric acid (2.125 g, 18.3 mmol) and P₂ O₅ (12.2 g) wereadded. The temperature was gradually raised to 120° C. over six hoursand then to 160° C. and finally to 180° C. This polymerization mixture,which became yellowish-brown in color, was allowed to proceed at 180° C.for 24 hours. The polymeric dope mixture was then precipitated in water.The precipitated polymer was purified by extraction in water for threedays.

The polymeric product, poly(benzobisimidazole vinylene) (PBIV), wascharacterized as follows:

FTIR (KBr pellet, cm⁻¹) 3300, 3010, 1629, 1388, 1297, 1238, 1151, 1015,960, 841, 669.

EXAMPLE 38 Preparation of Poly(benzobisimidazole Divinylene)

The dehydrochlorination reaction of TABH (2.2 g, 7.75 mmol) was repeatedin accordance with the procedure utilized in Example 1. The cooleddehydrochlorination reaction product was reacted withtrans,trans-muconic acid (1.1 g, 7.75 mmol) in accordance with theprocedure utilized in Example 2. P₂ O₅ added with the muconic acid in anamount to compensate for the water of condensation. The temperature ofthe thus formed reaction product was raised to 85° C. over two hours andheld at this temperature for six hours. Thereupon, the reactiontemperature was increased to 120° C. The viscosity of the reactionmixture rose rapidly with a corresponding color change from yellow toyellowish-green under the elevated 120° C. temperature. The reaction wasallowed to proceed for 14 hours at 120° C. during which time thepolymerization dope became stir opalescent. The polymerization dope wascooled to room temperature and precipitated in water. The fibrouspolymer thus formed was shredded into small pieces with a blender tofacilitate purification which was facilitated by extraction with waterfor 2 to 3 days.

The polymer product, poly(benzobisimidazole divinylene) (PBIDV), wascharacterized by Fourier Transfer Infrared (FTIR) and nuclear magneticresonance (NMR). The characterizing data were as follows:

FTIR(free standing film, cm⁻¹)3400, 3010, 1619, 1500, 1383, 1278, 1151,1091, 984, 828; ¹ H NMR(CD₃ NO₂ /AlCl₃, 300 MHz TMS) δ, ppm, 7.5(d,2H);8.0(d,2H); 8.4(d,2H); 9.1(s,2H).

EXAMPLE 39 Preparation of Poly(bibenzobisimidazole Divinylene)

3,3'-Diaminobenzidine (1.508 g, 7.04 mmol) was dehydrochlorinated with83.3 wt % deaerated PPA in accordance with the procedure enumerated inExample 1. The product of this dehydrochlorination was reacted withtrans, trans-muconic acid (1.0 g, 7.04 mmol) in accordance with theprocedure of Example 1. This polymerization reaction was conducted for atotal of 30 hours, the first 6 hours of which were at a temperature of100° C. and the final 24 hours at 140° C. The product of this reactionwas a yellowish-brown polymerization dope. This product was precipitatedin water and purified by extraction, for 3 days, with water.

The product of this polymerization reaction, poly(bibenzobisimidazoledivinylene) (PBBIDV), was characterized by Fourier Transfer Infrared(FTIR) and nuclear magnetic resonance (NMR). These characterizations areas follows:

FTIR (KBr pellet, cm⁻¹) 3400, 3010, 1627, 1504, 1458, 1287, 1249, 1081,995, 881; ¹ H NMR (CD₃ NO₂ /AlCl₃, 300 MHz, TMS) δ, ppm, 7.4 (s2H),7.9-8.4 (broad peaks, 8H), 9.0 (s,2H).

EXAMPLE 40 Preparation ofPoly(benzobisthiazole-1,4-phenylenebisvinylene)

2,5-Diamino-1,4-benzenedithiol (DABDT) (1.8 g, 4.08 mmol) was dissolvedin 77% deaerated PPA (25 g) under a nitrogen atmosphere in a glassreactor of the type described in Example 1. The resultantdehydrochlorination reaction was conducted after 30 minutes purge withnitrogen at 70° C. under vacuum.

The resultant reaction mixture was cooled to 50° C. and contacted with1,4-phenylene diacrylic acid (PDAA) (0.89 g, 4.08 mmol). P₂ O₅ (10.5 g)was added under positive pressure to compensate for the calculatedtheoretical water of condensation. The reaction mixture was raised to60° C. and held at this temperature for eight hours. The temperature wasfurther raised to 100°-120° C. and maintained in this temperature rangefor an additional 22 hours. The polymerization dope product of thisreaction was poured into a beaker and precipitated with 500 ml deionizedwater. The fibrous precipitate was shredded with a blender and purifiedby stirring in a large volume of deionized water for three days. Theproduct was dried in a vacuum oven at 60° C. and was obtained in a yieldof approximately 100%.

The product of this polymerization reaction,poly(benzobisthiazole-1,4-phenylenebisvinylene) (PBTPV), wascharacterized by both FTIR and ¹ H NMR spectra. These spectra were asfollows:

FTIR (free standing film cm⁻¹) 3033, 3000, 2923, 2852, 1622, 1558, 1516,1489, 1418, 1403, 1312, 1265, 1180, 1054, 949, 855, 804, 656; ¹ H NMR(CD₃ NO₂ /GaCl₃, 300 MHz, TMS) δ, ppm, 9.0 (s,2H), 8.4-8.5 (m,4H), 8.1(s,2H), 8.0 (s,2H).

EXAMPLE 41 Preparation of Poly(p-biphenylene Benzobisthiazole)

2,5-Diamino-1,4-benzenedithiol dihydrochloride (DABDT) (1.3 g, 5.3 mmol)was dehydrochlorinated in 77% deaerated PPA (13.7 g) in accordance withthe procedure of Example 1. The product-obtained in the glass reactor,was cooled to 50° C. and then 4,4'-diphenyldicarboxylic acid (1.28 g,5.3 mmol) and P₂ O₅ (6.7 g) were added under a nitrogen purge. Thereaction mixture, under slow stirring, was heated to 100° C. for 4hours, followed by heating at 140° C. for 8 hours and finally heating at180° C. for 24 hours.

The polymerization dope was allowed to cool to room temperature and thepolymer precipitated in water. The polymer was shredded into smallpieces with a blender to facilitate purification which involvedextraction with a large volume of water, over 2 days.

The product of this polymerization poly(p-biphenylene benzobisthiazole)(PBBZT), was characterized by nuclear magnetic resonance as follows:

[1H NMR:CD₃ NO₂ /AlCl₃, δ ppm: 9.2,2H; 8.5,4H; 8.3,4H].

EXAMPLE 42 Preparation of Poly(2,6-naphthyl Benzobisthiazole)

DABDT (1.0 g, 4.08 mmol), was dissolved in 77% deaerated PPA (9.8 g) anddehydrochlorinated at 70° C. 2,6-Naphthalene dicarboxylic acid (0.88 g,4.08 mmol) was added to the completely dehydrochlorinated product alongwith P₂ O₅ (5.0 g). The heating regime and purification steps used inthe polymerization of the polymer of Example 6 was repeated.

The product of this polymerization, poly(2,6-naphthyl benzobisthiazole)(2,6-PNBT), was characterized by nuclear magnetic resonance as follows:

[₁ HNMR:CD₃ NO₂ /AlCl₃, δ ppm: 9.3,2H; 8.5,4H; 8.2,2H].

EXAMPLE 43 Preparation of Poly(1,4-naphthyl Benzobisthiazole)

The procedure of Example 7 was identically reproduced except for thesubstitution of an identical amount of 1,4-naphthalene dicarboxylic acidfor the 2,6-naphthalene dicarboxylic acid of Example 7.

The product of this example, poly(1,4-naphthylbenzobisthiazole)(1,4-PNBT), was characterized by nuclear magnetic resonance as follows:

[¹ H NMR: CD₃ NO₂ /AlCl₃, δ ppm: 9.4,2H; 8.6,4H; 8.1,2H].

EXAMPLE 44 Preparation of Poly(benzobisthiazole Decamethylene)

The procedure of Example 6 was repeated but for the substitution ofdecanedioic acid for the 4,4'-biphenylene dicarboxylic acid of Example6.

This procedure resulted in the formation of poly(benzobisthiazoledecamethylene) (PBTC10). This polymer was characterized by both nuclearmagnetic resonance and infrared spectra as follows:

[¹ H NMR: CD₃ NO₂ /AlCl₃, δ ppm: 8.9,2H; 3.6,4H; 2.0,4H; 1.2-1.7, 12H].FTIR(free standing film, cm⁻¹) 2922, 2850, 1532, 1426, 1404, 1308, 1161,1054, 859.

EXAMPLES 45 TO 47 Preparation of Other Poly(benzobisthiazole Methylenes)

The synthesis of poly(benzobisthiazole docamethylene) of Example 9 wasrepeated in three additional examples wherein decanedioic acid wasreplaced with octanedioic acid, nonanedioic acid, and undecanedioicacid, respectively to produce poly(benzobisthiazole octamethylene)(PBTC8), poly(benzobisthiazole nonmethylene) (PBTC9), andpoly(benzobisthiazole undecamethylene) (PBTC11), respectively.

These polymers were characterized by nuclear magnetic resonance data asfollows:

(PBTC8)

¹ H NMR [δ, ppm: 1.2-1.7, 2.0, 3.6, 8.9]

PBTC9

¹ H NMR [δ, ppm: 1.2-1.7, 2.0, 3.6, 8.9]

PBTC11

¹ H NMR [δ, ppm: 1.2-1.7, 2.0, 3.6, 8.9]HOOC (CH₂)₈ COOH.

EXAMPLE 48 Preparation of Poly(benzobisthiazole Vinylene)

2,5-Diamino-1,4-benzenedithiol dihydrochloride (DABDT) (1.667 g, 6.8mmol) was dehydrochlorinated with 77% deaerated PPA (18.5 g) inaccordance with the procedure of Example 1. Fumaric acid (0.789 g, 6.8mmol) and P₂ O₅ (9 g) were added to the dehydrochlorinated product, thelatter compound to compensate for the water of condensation. Thetemperature was gradually raised to 120° C. over six hours and then to160° C. and finally to 180° C. The polymerization mixture became shinydark green and the reaction was allowed to proceed for eight hours at180° C. At that time the polymeric dope was precipitated in water. Thepolymer thus formed was shredded into tiny pieces with a blender tofacilitate purification. Purification involved extraction with water fortwo days.

The product of this polymerization, poly(benzobisthiazole vinylene)(PBTV), was characterized by FTIR spectra. This data is as follows:

FTIR (free standing film, cm⁻¹): 1663, 1600, 1515, 1400, 1313, 1052,944, 856, 689.

EXAMPLE 49 Preparation of Poly(benzobisthiazole Divinylene)

DABDT (4.31 g, 17.57 mmol) was dehydrochlorinated in accordance with theprocedure of Example 13. This product was then reacted withtrans,trans-muconic acid (2.5 g, 17.57 mmol) with the concurrentaddition of P₂ O₅ to compensate for the water of condensation. The thusformed mixture was raised to a temperature of 80° C. and held at thattemperature for six hours. The temperature was thereupon raised to 120°C. for 10 additional hours. The resultant polymerization product wasprecipitated in water and thereafter shredded into tiny pieces with ablender. The polymer was purified by extraction in water for 2 days.

The product of this polymerization reaction, poly(benzobisthiazoledivinylene) (PBTDV), was characterized by IR spectra data. This data isas follows:

FTIR (free standing film, cm⁻¹): 1601, 1480, 1400, 1315, 1053, 974, 845,680.

EXAMPLE 50 New Process for Preparing Polybenzobisthiazole

DABDT (3.87 g, 15.78 mmol) was dissolved in deaerated 77% PPA (14.66 g)and dehydrochlorinated at 70° C. under vacuum in accordance with theprocedure of Example 1. Oxalic acid (1.42 g, 15.78 mmol) was addedtogether with P₂ O₅ (12 g) under positive pressure. The temperature ofthis reaction mixture was gradually raised to 120° C. over ten hours,subsequently to 140° C. and finally to 180°-200° C. The reactioncontinued at this elevated temperature (180°-200° C.) for 24 hours. Thepolymerization dope in PPA was precipitated in water and purified byextraction of the PPA with water for two days.

The product of this polymerization reaction, polybenzobisthiazole(PBBT), was characterized by infrared spectra data. That data is asappears below:

FTIR (free standing film, cm⁻¹): 1467, 1406, 1313, 889, 860, 685.

EXAMPLE 51 Exciplex Formation from Poly(p-phenylene Benzobisoxazole) andTris(p-tolyl)amine

An isotropic solution of PBO in nitromethane with aluminum (III)chloride (AlCl₃) as prepared as described in Jenekhe, et al.,Macromolecules (1989), 22, 3216 and Jenekhe, et al., Macromolecules(1990), 23, 4419. Thin films of PBO were prepared by spin coating theresultant solution onto glass and fused silica substrates. The resultantcoatings of PBO/AlCl₃ complex were washed several times with deionizedwater and subsequently placed in a beaker of deionized water overnightto ensure complete decomplexation occurred. The films were then dried ina vacuum oven for 6 hrs. at 80° C. to obtain PBO-coated substrates. ThePBO thin film layer was approximately 50 nm thick.

Tris (p-tolyl) amine, TTA, was obtained from Eastman Kodak, Rochester,N.Y. A solution of TTA and poly(bisphenol A carbonate), PC, 40:60 byweight TTA:PC, in dichlormethane was prepared. The solution was spincoated onto the PBO-coated substrates. The resultant TTA/PC thin filmscontaining 40 weight % TTA, hereafter referred to as TTA layers, wereabout 200 nm thick. The result was a PBO/TTA bilayer thin film assembly.It was found that the rigid rod polymer PBO does not dissolve or swellin dichloromethane, CH₂ Cl. It was also found that the TTA layer can besubsequently washed off with CH₂ Cl to recover a pure PBO-coatedsubstrate.

Optical absorption spectra, photoluminescence (PC) spectra and PL decayexperiments were conducted on the PBO thin films, TTA thin films andPBO/TTA bilayer thin films. All photophysical measurements were made atroom temperature. UV-visible spectra were obtained on a Perkin ElmerLamba 9 spectrophotomer. Steady state photoluminescence studies weredone on a Spex Fluorolog-2-fluorimeter equipped with a DM3000Fspectroscopy computer. The polymer films on glass slides were positionedsuch that the emission was detected at 22.5° from the incident beam. Therelative PL quantum efficiency was obtained by comparing the integrationof the emission spectra of PBO/TTA bilayers to those of PBO films. Thesteady state PL spectra were obtained with excitation at 380 nm.

Time-resolved photoluminescence decay measurements were performed byusing time-correlated single photon counting technique. The excitationsystem consisted of a mode-locked frequency doubled Nd:YAG laser(Quantronics Model 416) synchronously pumping a cavity dumped dye laser(Coherent Model 703D) circulating rhodamine 6G. The Nd:YAG laser pulseswere typically 10 ps duration at a repetition rate of 38 MHz. PBO andPBO/TTA samples were photoexcited at 380 nm. Time-resolved PL decaymeasurements were also done on the single-layer TTA/PC thin films (about200 nm) by exciting at 300 nm, the λ_(max) of TTA's lowest energyabsorption band. The excitation at 300 nm was obtained by frequencydoubling of the output of a dye laser (Rhodamine 6G).

FIG. 4 shows the optical absorption spectra of thin films of TTAdispersed in the matrix of polycarbonate, PBO, and PBO/TTA. As seen inFIG. 4, the absorption maximum (λ_(max)) of the lowest energy absorptionband of the TTA films, Curve 3, is 300 nm. The lowest energy absorptionband of PBO thin film, Curve 1, has peaks (λ_(max)) at 401 and 427 nm,similar to its absorption spectrum as reported by Jenekhe, et al. inChem. Mater. (1992), 4683. The optical absorption spectrum of thePBO/TTA bilayer thin film shown in FIG. 4, is composed of the componentspectra. There are no new features or absorption bands in the spectrumof PBO/TTA bilayer, which new features or absorption bands wouldindicate strong interaction between PBO and TTA in the ground state.This result is in accord with the weak electron accepting properties ofPBO in the ground state.

FIG. 5 shows the photoluminescence (PL) spectrum of a PBO thin film,Curve 3, excited at 380 nm. The PL spectrum has a peak at 500 nm,indicating green light emission. The PL spectra of PBO thin filmsexcited at wavelengths in the spectral range 380-440 nm were identicalwith the one shown in FIG. 5, suggesting that emission is from the samestate. Although measurement of the absolute fluorescence quantumefficiency Φ_(f) in the solid state is very difficult, as related byDemas, et al. in J. Phys. Chem. (1971), 75, 991, it was neverthelessestimated for the present example relative to other conjugated polymersthat have been measured. PBO thin films are about 30% more fluorescentthan poly(p-phenylene vinylene) and about a factor of 2 more fluorescentthan poly(benzobisthiazole-1,4-phenylene-bisvinylene (PBTPV) reported byOsaheni, J. A., et al. in Macromolecules (1993), 26, 4726. The emissionspectrum of the pure TTA layer, Curve 1, shown in FIG. 5, corresponds toexcitation at 300 nm and has a monomer emission peak at 380 nm,indicating ultraviolet emission, and an excimer emission at 432 nm.Excitation of pure TTA layer at 380 nm showed a very weak emission at440 nm that was at least a factor of 10 weaker in intensity compared tothe emission from 300 nm excitation.

An exciplex of PBO/TTA was formed by exciting the PBO/TTA bilayer thinfilm. FIG. 5 shows the PL spectrum of a PBO/TTA bilayer thin film, Curve2, excited at 380 nm. A highly intense bright blue emission with peak at474 nm was observed. The emission peak of PBO/TTA was blue shifted by 26nm from the emission peak of the pure PBO. Most dramatic of all thedifferences between PBO/TTA and PBO was the enhancement by a factor of3.4 of the fluorescence quantum efficiency of PBO/TTA compared to thepure PBO.

Time-resolved photoluminescence decay dynamics of PBO/TTA and PBO thinfilms confirmed the observed enhancement of the luminescence in PBO/TTAto originate from an excited state that is distinctively different fromthat of either component. The decay dynamics of PBO and of PBO/TTAexcited at 380 nm were very different, reflecting the different excitedstates of the materials. The decay of PBO showed that the longestlifetime was 0.66 ns. However, the major component of the decay of theexcited state associated with PBO/TTA had a lifetime of 4.6 ns. TTAlayer excited at 300 nm also exhibited a different decay dynamics withthe major component having a lifetime of 2.9 ns.

EXAMPLES 52-58

Examples 52-58 were prepared and subsequent measurements were all madein accordance with the procedures set forth in Example 51. Thin films ofthe following π-conjugated polymers were prepared on glass or fusedsilica substrates:

    ______________________________________    Example           π-Conjugated Polymer    ______________________________________    52     poly(p-phenylene benzobisthiazole), PBZT    53     poly(p-biphenylene benzobisthiazole), PBBZT    54     poly(1,4-naphthyl-benzobisthiazole), 1,4-PNBT    55     poly(benzobisthiazole-1,4-phenylenebisvinylene),           PBTPV    56     poly(benzobisthiazole vinylene), PBTV    57     poly(benzobisthiazole divinylene), PBTDV    58     poly(p-phenylene benzobisoxazole), PBO    ______________________________________

Solutions of TTA dispersed in polycarbonate in a weight ratio of 40:60were prepared in accordance with Example 51 and were spun coated ontothe π-conjugated polymer-coated substrates of Examples 52-58. The filmthickness of TTA/PC atop each of the polymers of Examples 52-58 was 55nm.

Optical absorption spectra (X_(max)) and the photoluminescence (λ_(max))spectra of the pure polymers are given in Table 1. The exciplexes wereformed in accordance with Example 1 by photoexcitation at 380 nm, andthe photoluminescence spectra (λ_(max)) for each of the exciplexes thusformed were taken and appear (λ_(max)) at Table 1. Also shown in Table 1is the relative luminescence enhancement factor, Φ_(expl) /Φ_(o) of eachof Examples 52-58 exciplex to the pure polymers thereof; and thereduction potential, E° red, of each of the pure polymers of Examples52-58, given as V vs. SCE.

                                      TABLE 1    __________________________________________________________________________     ##STR125##          ##STR126##                ##STR127##                      ##STR128##                           ##STR129##                                ##STR130##                                     ##STR131##    __________________________________________________________________________    52   35    438   564  512  3.5  -1.75    53   40    415   536  490  3.8  -1.80    54   30    436   572  542  3.5  -1.70    55   40    475   640  560  3.4  -1.68    56   20    468   618  588  3.6  -1.46    57   25    500   640  592  3.8  -1.45    58   15    401   502  474  4.2  -1.92    __________________________________________________________________________

As can be seen from Table 1, the exciplexes of each of Examples 52-58all showed an emission peak, λ_(max), shifted to shorter wavelengthsthan the emission peak λ_(max), of the pure polymer, with the exciplexof PBO/TTA, Example 58), emitting, at peak, a deep blue color at 474 nm.

Also as can be seen at Table 1, the relative luminescence enhancementfactor, Φ_(expl) /Φ_(o), of the exciplex relative to the pure polymershows that the light emission of the exciplex is far more efficient thanthat of the pure polymer. Thus, for example, the luminescence of thePBO/TTA exciplex of Example 58 at λ_(max) =474 nm, was a factor of 4.2,or 420%, more efficient than the luminescence of the single-layer PBOfilm alone.

Also, as seen in Table 1, the peak luminescence, λ_(max), of theexciplexes are linear with the reduction potential of the pure polymers,E° red., thus permitting the color of the light emitted to be tuned byparing suitable materials having the desired E° red. for the particularexciplex to be formed.

EXAMPLE 59 Photogeneration of Charge

A bilayer assembly consisting of 0.1 μm thick PBZt and 10 μm thickTTA/PC (40:60 wgt % TTA:PC) was prepared substantially as described inExample 51. The assembly was disposed atop a substrate comprised ofnickel-coated poly(ethylene terephthalate) such that the TTA layer wasthe top (free surface) layer. The final assembly is illustrated at FIG.6A. Xerographic photodischarge measurements were made to determine thecharge photogeneration efficiency of the bilayer device assembly as afunction of applied electric field.

To instigate photogeneration of charge, a surface charge was applied tothe top of the TTA layer by corona charging, followed by photoexcitationof the PBZT layer. The PBZT/TTA exciplex to form a PBZT/TTA exciplexwhere PBZT acted as an electron acceptor and TTA acted as an electrondonor. The photocarrier generation mechanism in the bilayer PBZT/TTAassembly consisted of electric field-assisted dissociation of theexciplex, the mechanism being represented as PBZT*+TTA→(PBZT*TTA)→(PBZT⁻. TTA⁺.)→PBZT⁻. +TTA⁺.

As shown in FIG. 7, the charge photogeneration efficiency, Φ, variedfrom about 10% at low fields (less than about 10⁴ V/cm) to 31% at fieldsof about 10⁶ V/cm. In comparison, the charge photogeneration efficiencyof the individual components, PBZT and TTA, were too small to bemeasurable.

EXAMPLES 60 TO 71 Light Emitting Properties of Polymeric Films

Polymeric films were tested to determine their light emitting propertiesby imposing a voltage across the light emitting diodes prepared inExample 50. This determination involved providing a voltage source inelectrical communication with the electrical conduits connected to thealuminum layer and the conductive indium tin oxide layer of the glasssubstrate.

Initially, an EMF of 1 volt was applied. This was slowly increased to amaximum of about 20 volts. The wavelength color and intensity of anylight emission resulting therefrom was observed. From this data thequantum efficiency of fluorescence, Φ_(f) is determined. Φ_(f) is thefraction of the excited carriers that combine radioactively. The higherthis quantum efficiency the better is the polymer as a light emittingsource most polymers do not possess this property and have a Φ_(f) of O.

The polymeric films, within the contemplation of the present invention,which were tested as light emitters are summarized in the Table 2 below.This table includes Φ_(f), the wavelength of maximum light emission andthe color of that light emission.

                  TABLE 2    ______________________________________    Exam    Light           Thin Film Wavelength of                                          Color of    No.   Polymer   Φ.sub.f, %                              Max. Emission, nm                                          Emitted    ______________________________________    60    PBO.sup.1 10.4      500         Green    61    PBZT.sup.2                     8.0      560         Yellow    62    PBTPV     4.0-5.0   640         Red    63    2,6-PNBT  4.0-5.0   578         Yellow    64    1,4-PNBT  4.0-5.0   572         Yellow    65    PBBZT     4.0-5.0   536         Green    66    BBL.sup.3 <10.sup.-3                              740         Near                              Infrared    67    PBIV      <10.sup.-3                              620         Orange    68    PBIDV     <10.sup.-3                              652         Red    69    PBIPV     <10.sup.-3                              638         Red    70    PBZI      <10.sup.-3                              560         Yellow    71    PBBI      <10.sup.-5                              Below S/N.sup.4                                          --    ______________________________________     .sup.1 Poly(p-phenylene benzobisoxazole)     .sup.2 Poly(pphenylene benzobisthiazole)     .sup.3 Polybenzimidozolebenzophenyanthiolanetype ladder (Polymeric having     repeating structure of Formula XIII)     .sup.4 Signal to Noise ratio.

What is claimed is:
 1. A composition comprising an exciplex of aπ-conjugated polymer first component and an electron donor or electronacceptor second component, said second component different from saidfirst component and effective to form said exciplex with said firstcomponent when at least one of said first component or said secondcomponent is in an excited state.
 2. The composition of claim 1 whereinsaid π-conjugated polymer comprises a repeating unit having thestructure: ##STR132## wherein Y is ##STR133## Ar is a monocyclic orpolycyclic aromatic moiety having 6 to 18 ring atoms in said moiety or anitrogen-, oxygen- or sulfur-containing heterocyclic moiety having from5 to 18 ring atoms in said moiety, any one of which moieties may beunsubstituted or substituted with one or more lower alkyl, lower alkoxy,aryl, alkaryl, aralkyl, aroxy, nitro, hydroxy or halogen groups;X and X₁are each independently NR, oxygen or sulfur and each R is independentlyhydrogen or lower alkyl; Ar₁, Ar₂, Ar₃ and Ar₄ are each independently amonocyclic or polycyclic aromatic moiety having 6 to 8 ring atoms insaid moiety or a nitrogen-, oxygen- or sulfur-containing heterocyclicmoiety having 5 to 18 ring atoms in said moiety, any of which moietiesmay be unsubstituted or substituted with one or more lower alkyl, loweralkoxy, aryl, alkaryl, aralkyl, aroxy, nitro, hydroxy or halogen groups;R₁, R₂, R₃ and R₄ are each independently vinylene or ethynylene; X₂, X₅,X₆ and X₉ are each independently nitrogen or CR₅, and X₃, X₄, X₇ and X₈are each independently nitrogen or CR₅ when not forming a point ofattachment, with the proviso that at least one but no more than two ofX₂, X₃, X₄ and X₅ is nitrogen and at least one but no more than two ofX₅, X₆, X₇ and X₅ is nitrogen and each R₅ is independently hydrogen,nitro, halogen, lower alkyl, lower alkoxy, alkaryl, aralkyl, amonocyclic or polycyclic aromatic moiety having 6 to 18 ring atoms insaid moiety or a nitrogen-, oxygen- or sulfur-containing heterocyclicmoiety having 5 to 18 ring atoms in said moiety, any of which may beunsubstituted or substituted with one or more halogen, lower alkyl,lower alkoxy or aroxy groups; a, b, c and d are each independently 0 oran integer from 1 to 12; e, f, g and h are each independently 0 or aninteger from 1 to 6; and n is an integer from 2 to
 2000. 3. Thecomposition of claim 2 whereinY has Formula I; and Ar is a monocyclic orpolycyclic aromatic moiety having 6 to 12 ring atoms in said moiety. 4.The composition of claim 3 whereinAr is ##STR134## X and X₁ are eachsulfur; and Ar₁ and Ar₂ are each independently a monocyclic orpolycyclic aromatic moiety having 6 to 10 ring atoms in said moiety. 5.The composition of claim 4 whereinAr₂ is ##STR135## c is 2; and a, b andd are each zero.
 6. The composition of claim 4 whereinAr₂ is ##STR136##c is 1; and a, b and d are each zero.
 7. The composition of claim 4whereinAr₂ is ##STR137## c is 1; and a, b and d are each zero.
 8. Thecomposition of claim 4 whereinR₁ and R₂ are each vinylene; Ar₂ is##STR138## b, c and d are each 1; and a is zero.
 9. The composition ofclaim 4 whereinR₂ is vinylene; d is 2; and a, b, and c are each zero.10. The composition of claim 4 wherein R₂ is vinylene; d is 1; and a, band c are each zero.
 11. The composition of claim 4 whereinAr is##STR139## c is 1; and a, b and d are each zero.
 12. The composition ofclaim 3 whereinAr is ##STR140## X and X₁ are each NR; and Ar₁ and Ar₂are each independently a monocyclic or polycyclic aromatic moiety having6 to 10 ring atoms in said moiety.
 13. The composition of claim 12whereinX and X₁ are each NH; and a, b, c and d are each zero.
 14. Thecomposition of claim 12 whereinX and X₁ are each NH; Ar₂ is ##STR141## cis 1; and a, b and d are each zero.
 15. The composition of claim 12whereinX and X₁ are each NH; R₂ is vinylene; d is 2; and a, b and c areeach zero.
 16. The composition of claim 12 whereinX and X₁ are each NH;R₂ is vinylene; d is 1; and a, b and c are each zero.
 17. Thecomposition of claim 12 whereinX and X₁ are each NH; R₁ and R₂ are eachvinylene; Ar₁ is ##STR142## b, c and d are each 1; and a is zero. 18.The composition of claim 3 whereinAr is ##STR143## and X and X₁ are eachindependently NR.
 19. The composition of claim 18 whereinX and X₁ areeach NH; R₂ is vinylene; d is 2; and a, b and c are each zero.
 20. Thecomposition of claim 2 whereinY has Formula II; and Ar is a monocyclicor polycyclic aromatic moiety having 6 to 12 ring atoms in said moiety.21. The composition of claim 20 whereinAr is ##STR144## and X and X₁ areeach oxygen.
 22. The composition of claim 21 whereinAr₂ is ##STR145## cis 1; and a, b and d are each zero.
 23. The composition of claim 2whereinY has Formula III; and Ar is a monocyclic or polycyclic aromaticmoiety having 6 to 12 ring atoms in said moiety.
 24. The composition ofclaim 23 whereinAr is ##STR146## and a, b, c and d are each zero. 25.The composition of claim 23 whereinAr is ##STR147## a is 1; and b, c andd are each zero.
 26. The composition of claim 2 whereinY is Ar.
 27. Thecomposition of claim 26 whereinAr is a monocyclic aromatic moiety. 28.The composition of claim 27 whereinAr is ##STR148## and a, b, c and dare each zero.
 29. The composition of claim 27 whereinAr is ##STR149##R₂ is vinylene; d is 1; and a, b and c are each zero.
 30. Thecomposition of claim 26 wherein Ar is a nitrogen-containing heterocyclicmoiety.
 31. The composition of claim 30 whereinAr is ##STR150## and a,b, c and d are zero.
 32. The composition of claim 26 whereinAr is asulfur-containing heterocyclic moiety.
 33. The composition of claim 32whereinAr is ##STR151## and a, b, c and d are each zero.
 34. Thecomposition of claim 32 whereinAr is ##STR152## R₂ is vinylene; d is 1;and a, b and c are each zero.
 35. The composition of claim 2 whereinYhas Formula VII.
 36. The composition of claim 35 whereinX₂ and X₆ areeach nitrogen; X₃ and X₇ are each points of attachment; X₄, X₅, X₈ andX₉ are each independently CR₅ ; and e, f, g and h are each zero.
 37. Thecomposition of claim 36 wherein the R₅ associated with X₄ and the R₅associated with X₈ are each hydrogen; and the R₅ associated with X₅ andthe R₅ associated with X₉ are each phenyl.
 38. The composition of claim37 whereinR₂ is vinylene; d is 1; and a, b and c are each zero.
 39. Thecomposition of claim 37 whereinR₂ is ethynylene; d is 1; and a, b and care each zero.
 40. The composition of claim 37 whereinAr₁ and Ar₂ areeach ##STR153## R₂ is ethynylene; a, c and d are each 1; and b is zero.41. The composition of claim 37 whereinAr₂ is ##STR154## c is 1; and a,b and d are each zero.
 42. The composition of claim 37 whereinAr₂ is##STR155## c is 2; and a, b and d are each zero.
 43. The composition ofclaim 37 whereinAr₁ and Ar₂ are each ##STR156## R₂ is vinylene; a, c andd are each 1; and b is zero.
 44. The composition of claim 37 whereinAr₁and Ar₂ are each ##STR157## R₂ is ethynylene; a, c and d are each 1; andb is zero.
 45. The composition of claim 2 whereinY has Formula VI. 46.The composition of claim 45 whereinX₂ and X₉ are each nitrogen; X₃ andX₈ are each points of attachment; and X₄, X₅, X₆ and X₇ are eachindependently CR₅.
 47. The composition of claim 46 wherein the R₅associated with X₄ and the R₅ associated with X₇ are each hydrogen; andthe R₅ associated with X₅ and the R₅ associated with X₆ are each phenyl.48. The composition of claim 47 whereinR₂ is vinylene; d is 1; and a, band c are each zero.
 49. The composition of claim 47 whereinR₂ isethynylene; d is 1; and a, b and c are each zero.
 50. The composition ofclaim 47 whereinAr₁ and Ar₂ are each ##STR158## R₂ is vinylene; a, c andd are each 1; and b is zero.
 51. The composition of claim 47 whereinAr₁and Ar₂ are each ##STR159## R² is ethynylene; a, c and d are each 1; andb is zero.
 52. The composition of claim 47 wherein Ar₂ is ##STR160## cis 1; and a, b and d are each zero.
 53. The composition of claim 47whereinAr₂ is ##STR161## c is 2; and a, b and d are each zero.
 54. Thecomposition of claim 47 whereinAr₁ and Ar₂ are each ##STR162## R₂ isvinylene; a, c and d are each 1; and b is zero.
 55. The composition ofclaim 47 whereinAr₁ and Ar₂ are each ##STR163## R₂ is ethynylene; a, cand d are each 1; and b is zero.
 56. The composition of claim 35whereinX₂ and X₆ are each nitrogen; X₃ and X₇ are each points ofattachment; X₄, X₅, X₈ and X₉ are each independently CR₅ ; f is 1; ande, g and h are each zero.
 57. The composition of claim 56 wherein the R₅associated with X₄ and the R₅ associated with X₈ are each hydrogen; andthe R₅ associated with X₅ and the R₅ associated with X₉ are each phenyl.58. The composition of claim 57 whereinAr₂ is ##STR164## c is 2; R₃ isethynylene; and a, b and d are each zero.
 59. The composition of claim58 wherein the phenyls associated with X₅ and X₉ are eachhalogen-substituted.
 60. The composition of claim 59 wherein eachhalogen-substituted phenyl has the structure ##STR165##
 61. Thecomposition of claim 58 wherein the phenyls associated with X₅ and X₉are each substituted with alkoxy of up to 4 carbon atoms.
 62. Thecomposition of claim 61 wherein each alkoxy-substituted phenyl has thestructure ##STR166##
 63. The composition of claim 37 whereinAr₂ is##STR167## c is 1; and a, b and d are each zero.
 64. The composition ofclaim 37 whereinAr₂ is ##STR168## c is 2; and a, b and d are each zero.65. The composition of claim 37 whereinAr₂ is ##STR169## c is 3; and a,b and d are each zero.
 66. The composition of claim 47 whereinAr₂ is##STR170## c is 1; and a, b and d are each zero.
 67. The composition ofclaim 47 whereinAr₂ is ##STR171## c is 2; and S a, b and d are eachzero.
 68. The composition of claim 47 whereinAr₂ is ##STR172## c is 3;and a, b and d are each zero.
 69. The composition of claim 57 whereinAr₂is ##STR173## c is 1; R₃ is vinylene; and a, b and d are each zero. 70.The composition of claim 57 whereinAr₂ is ##STR174## c is 2; R₃ isvinylene; and a, b and d are each zero.
 71. The composition of claim 57whereinAr₁ and Ar₂ are each ##STR175## R₂ is ethynylene; R₃ is vinylene;a, c and d are each 1; and b is zero.
 72. The composition of claim 57whereinAr₁ and Ar₂ are each ##STR176## R₂ and R₃ are each vinylene; a, cand d are each 1; and b is zero.
 73. The composition of claim 57whereinAr₂ is ##STR177## R₃ is vinylene; c is 2; and a, b and d are eachzero.
 74. The composition of claim 57 whereinAr₂ is ##STR178## c is 3;R₃ is vinylene; and a, b and d are each zero.
 75. The composition ofclaim 57 whereinAr₂ is ##STR179## c is 2; R₃ is vinylene; and a, b and dare each zero.
 76. The composition of claim 75 wherein the phenylsassociated with X₅ and X₉ are each halogen substituted.
 77. Thecomposition of claim 76 wherein the halogen-substituted has thestructure ##STR180##
 78. The composition of claim 75 wherein the phenylsassociated with X₅ and X₉ are each substituted with alkoxy of up to 4carbon atoms.
 79. The composition of claim 78 wherein eachalkoxy-substituted phenyl has the structure: ##STR181##
 80. Thecomposition of claim 1 wherein said π-conjugated polymer comprises arepeating unit having the structure: ##STR182## wherein n is an integerfrom 2 to
 2000. 81. The composition of claim 1 wherein said π-conjugatedpolymer comprises a repeating unit having the structure: ##STR183##wherein n is an integer from 2 to
 2000. 82. The composition of claim 1wherein said π-conjugated polymer comprises a repeating unit having thestructure: ##STR184## wherein R₆ and R₈ are each independently vinylene,ethynylene, a monocyclic or polycyclic aromatic moiety having 6 to 18ring atoms in said moiety or a nitrogen-, oxygen- or sulfur-containingheterocyclic moiety having from 5 to 18 ring atoms in said moiety, anyof which moieties may be unsubstituted or substituted with one or morelower alkyl, lower alkoxy, aryl, alkaryl, aralkyl, aroxy, halogen, nitroor hydroxy groups;R₇ and R₉ are each independently hydrogen, loweralkyl, alkaryl, aralkyl or aryl; i and j are each independently 0 or aninteger from 1 to 12; and n is an integer from 2 to
 2000. 83. Thecomposition of claim 82 wherein said repeating unit has Formula XI andR₇ and R₉ are each hydrogen.
 84. The composition of claim 83 whereinR₆and R₈ are each ##STR185## and i and j are each
 1. 85. The compositionof claim 20 whereinAr is ##STR186## Ar₂ is ##STR187## c is 1; and a, band d are each zero.
 86. The composition of claim 1 wherein saidπ-conjugated polymer comprises a repeating unit having the structure:##STR188## wherein Ar₅ is ##STR189## and Ar₆ is ##STR190## wherein Ar₇is ##STR191## wherein Ar₈ is ##STR192## Ar₅ has the meaning given above,X₁₀ and X₁₁ are each independently sulfur, oxygen or NR₅ wherein R₅ ishydrogen, lower alkyl, lower alkoxy or an aryl group: ##STR193## whereinAr₉ is ##STR194## and X₁₀ has the meaning given above ##STR195## whereinAr₁₀ is ##STR196## wherein Ar₅, X₁₀ and X₁₁ have the meanings givenabove; and n is an integer from 2 to
 2000. 87. The composition of claim1 wherein said electron donor has an oxidation potential less than thatof said π-conjugated polymer and a reduction potential greater than thatof said π-conjugated polymer.
 88. The composition of claim 1 whereinsaid electron acceptor has an oxidation potential greater than that ofsaid π-conjugated polymer and a reduction potential less than that ofsaid π-conjugated polymer.
 89. The composition of claim 1 wherein saidsecond component is:a monocyclic or polycyclic aromatic compound havingfrom 6 to 18 ring atoms in said compound, a nitrogen-, oxygen- orsulfur-containing heterocyclic compound having from 5 to 18 ring atomsin said compound any one of which compounds may be unsubstituted orsubstituted with one or more lower alkyl, lower alkoxy, aryl, aralkyl,alkaryl, aroxy, cyano, nitro, hydroxy or halogen groups, anitrogen-containing compound having the structure: ##STR197## whereinR₁₀, R₁₁, R₁₂ and R₁₃ are each independently hydrogen, lower alkyl,aryl, aralkyl or alkaryl wherein any of said aryl, aralkyl or alkarylgroups may be substituted with one or more lower alkyl groups; Ar is amonocyclic or polycyclic aromatic moiety having 6 to 18 carbon atoms insaid moiety, which moiety may be unsubstituted or substituted with oneor more lower alkyl groups with the proviso that in Formula XII not morethan two of R₁₀, R₁₁ or R₁₂ are hydrogen, a π-conjugated polymerdifferent from said π-conjugated polymer first component, or a polymerhaving a repeating unit that contains a moiety of said monocyclic orpolycyclic aromatic compound or of said nitrogen-, oxygen orsulfur-containing heterocyclic compound.
 90. The composition of claim 89wherein said monocyclic or polycyclic aromatic compound is anthracene,9,10-dicyanoanthracene, tetracyanobenzene or 9,10-dimethylanthracene.91. The composition of claim 89 wherein R₁₀ and R₁₁ are each lower alkyland R₁₂ is aryl.
 92. The composition of claim 89 wherein saidnitrogen-containing compound is N,N-dimethylaniline,N,N'-diethylaniline,N,N'-diphenyl-N-N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine,tri(p-dimethylaminophenyl)amine or tris(p-tolyl)amine.
 93. Thecomposition of claim 5 wherein said electron donor or acceptor componentis tri(p-tolyl)amine.
 94. The composition of claim 7 wherein saidelectron donor or acceptor component is tris(p-tolyl)amine.
 95. Thecomposition of claim 8 wherein said electron donor component istris(p-tolyl)amine.
 96. The composition of claim 9 wherein said electrondonor component is tris(p-tolyl)amine.
 97. The composition of claim 10wherein said electron donor component is tris(p-tolyl)amine.
 98. Thecomposition of claim 11 wherein said electron donor component istris(p-tolyl)amine.
 99. The composition of claim 22 wherein saidelectron donor component is tris(p-tolyl)amine.